Comparison of isometric ankle strength between females with and without patellofemoral pain syndrome

Ana Paula de Moura Campos Carvalho e Silva, PT, MSc Student1 Eduardo Magalhães, PT, Msc2 Flavio Fernandes Bryk, PT3 Thiago Yukio Fukuda, PT, PhD3


Patellofemoral pain syndrome (PFPS) is the most common source of anterior knee pain in athletes and sedentary women, representing 20 to 40% of all individuals that are treated for knee injuries in orthopedic rehabilitation centers. Traditionally, the treatment of PFPS has focused on addressing structures about the knee joint, including quadriceps strengthening and hamstring and iliotibial flexibility, in order to decrease patellar maltracking and normalize patellofemoral contact. Recently, PFPS has been related to dynamic lower limb malalignment including excessive femoral medial rotation and adduction during eccentric daily activities, resulting in reduction of contact area in the patellofemoral joint. However the dynamic increase of tibiofemoral internal rotation could also decrease the patella to femur contact. Excessive or prolonged rearfoot eversion during gait could lead to a compensatory mechanism, causing an increase tibiofemoral internal rotation and consequently an excessive dynamic valgus. Baldon et al observed that greater rearfoot eversion (pronation of the foot) was associated with greater tibial internal rotation in subjects with PFPS. Based upon these biomechanical findings, many authors have recommended the use of foot orthoses to positively affect the alignment of the lower extremities, resulting in significant short and long-term satisfactory clinical outcomes. Thus, controlling excessive foot pronation may decrease the tibial and femoral internal rotation, thereby decreasing overload of the patellofemoral joint. The authors of this study believe that excessive foot pronation and calcaneal eversion during the midstance phase of gait could be the result of a muscular imbalance, related to dorsiflexor and invertor musculature weakness, especially the tibialis posterior muscle, which is assists in maintaining the medial longitudinal arch. With these concepts in mind, Barton et al17 and Powers et al18 suggested that increased foot pronation may be contributing factor in PFPS. Therefore, the aim of the current study was to compare the ankle dorsiflexor and invertor muscles strength, as well as rearfoot eversion and NDT in females with PFPS to a control group of females of similar demographics without PFPS. The authors hypothesized that when compared to a pain-free control group, females with PFPS would exhibit decreased ankle strength and increased rearfoot eversion and navicular drop. This study may help in the clinical understanding of the relationship between ankle muscle strength and PFPS. METHODS Subjects Twenty females between the ages of 20 and 40 years (mean 23.0 ± 3.0 years; height 162.0 ± 7.0 cm; body mass 56.8 ± 10.0 kg) diagnosed with unilateral (n=7) or bilateral (n=13) PFPS were recruited from the Physical Therapy sector of the Irmandade Santa Casa de Misericordia de São Paulo Hospital. The inclusion criteria for the PFPS group were the same criteria described by Thomee et al.19 Pain during at least 3 of the following activities: squatting, climbing up or down stairs, kneeling, sitting for long periods, or when performing resisted isometric knee extension at 60 degrees of knee flexion; insidious onset of symptoms unrelated to trauma and persistence for at least 4 weeks; and pain on palpation of the medial or lateral facet of the patella. Twenty control females (mean ± SD age, 24.0 ± 3.0 years; height, 163.0 ± 6.0 cm; body mass, 61.9 ± 10 kg), who presented with upper extremity tendinopathies and without lower extremity involvement were recruited from the same sector to serve as the control group. The exclusion criteria for both groups included the presence of any other associated knee conditions including patellar instability, patellofemoral joint dysplasia, meniscal or ligament injuries, tendon or cartilage injury, a decrease of range of motion in dorsiflexion, and a history of inversion injuries within the last 2 years. Subjects were also excluded if they had any neurological diseases, previous surgery of the lower limbs, lumbar pain, sacroiliac joint pain, rheumatoid arthritis, or were pregnant. It is important to highlight that all females included in both groups were active, but not competitive athletes.20 Before taking part in this study, the subjects were informed of the procedures and signed an informed consent approved by the Ethics Committee on Research of the ISCMSP.


A senior physical therapist determined subject participation in both groups based on the inclusion and exclusion criteria. The subjects completed the Anterior Knee Pain Scale (AKPS) and a verbal numeric pain rating scale (NPRS). Another evaluator, who was blinded to group assignment, measured all subjects for the NDT and rearfoot eversion bilaterally, followed by ankle manual muscle strength assessment. The data for pain, function, duration of symptoms, ankle strength, rearfoot eversion and NDT for the PFPS group were obtained from the affected limb of the subjects with unilateral PFPS and the most affected limb of subjects with bilateral PFPS. In relation to control, the authors used the mean value of both sides for data analysis.


Evaluation The Anterior Knee Pain Scale (AKPS) was used to measure self-reported function. The AKPS contains 13 items, each based on a 6-point scale, where the highest score represents no difficulty when performing the task and the lowest score represents complete inability to perform the activity. The maximum score is 100 and indicates that there is no deficiency; a score below 70 suggests moderate pain and disability. This questionnaire is reliable and valid, and has been widely used for patients with PFPS. Pain was measured with an verbal 11-point Numeric Pain Rating Scale (NPRS) where 0 corresponded to no pain and 10 corresponded to “worst imaginable pain”.

Foot evaluation

Foot pronation was assessed using the NDT. This test measures the difference in millimeters of the navicular tuberosity from the ground between a relaxed, weight bearing position, and a position of “imposed” subtalar neutral in standing. Initially, the subjects were placed on a rigid surface and placed in a neutral subtalar joint position, and the navicular height was measured. Next, the subjects were asked to relax and stand in their preferred posture, and the measurement was repeated. In the authors’ laboratory the reliability for NDT, was 0.80 (ICC2,1) and SEM 0.20mm. Then, the therapist passively positioned the calcaneus in maximum eversion and motion was measured with a goniometer, and named rearfoot eversion. The reliability for rearfoot eversion in the authors’ laboratory28 was 0.82 (ICC2,1) and SEM 0.75 degrees.


Muscle Strength A Nicholas hand-held dynamometer (Lafayette Instrument Company, Lafayette, IN) was used to measure isometric strength during a “make test” of the ankle dorsiflexors and invertors. This instrument is widely used clinically to measure muscle isometric strength. The dorsiflexor ankle strength was assessed while the subject lying in a supine position. The evaluated limb was positioned with the extended knee and the ankle joint remained in an unrestrained and neutral position. The dynamometer was placed against the dorsal surface of the foot near the metatarsal heads (FIGURE 1-A). In the authors’ laboratory, reliability for isometric muscle strength measurement of the dorsiflexors was 0.95 (ICC2,1) and SEM of 1.00 kg. The invertor muscles were evaluated with the subject in the same position and the dynamometer was placed on the medial border of the foot at the shaft midpoint of the first metatarsal. In the authors’ laboratory, reliability for isometric muscle strength measurement of the invertors was 0.77 (ICC2,1) and SEM 1.97 kg. During isometric strength testing, two submaximal trials were allowed for the subject to become familiar with each test position. This was followed by two trials with the subject providing maximal isometric effort for each muscle group, using consistent verbal encouragement. The interval between the second submaximal contraction and the first maximum isometFigure 1. Strength measurement for the dorsifl exor (A) and invertor (B) musculature IJSPT ric contraction was 10 seconds. The duration of each maximum isometric contraction was standardized at 5 seconds, with a rest time of 30 seconds between maximum isometric contractions. Testing order for the muscle groups was randomized. After evaluation of a muscle group, a standard 1-minute rest period was given before evaluating the other muscle group. When the examiner observed any compensation or combined movements during a test, the values were disregarded and the test was repeated after 20 seconds of rest. The mean values of the two maximal effort trials (one mean for each of the tested muscle groups) were utilized for data analysis.

Data Reduction

Isometric strength measurements, measured in kilograms (Kg), were normalized to body mass, also reported in Kg by using the following formula: (Kg strength / Kg body weight) x 100.29,33

Data Analysis

Normality was assessed using Shapiro-Wilk test. Independent t-test were used to measure and compare demographics data, NPRS scores, AKPS scores, normalized dorsiflexor and invertor isometric strength; and the Mann-Whitney test was used to compare the NDT and rearfoot eversion measurements between groups. SigmaStat 3.5 was used for data analysis and the alpha level was set at 0.05.


Demographic data for the PFPS group and the control group are provided in Table 1. The PFPS and the control group were not statistically different in terms of age, weight, and height (p>0.05). Dorsiflexor and invertor muscle strength, NDT measurements, and the rearfoot eversion measurements of both groups are presented in Table 2. There were no statistically significant differences in normalized dorsiflexor (p=0.80) and invertor (p=0.60) muscle strength between the PFPS group and the control group. Moreover, the NDT and the rearfoot eversion measurements were not significantly different (p = 0.40 and p = 0.30, respectively) between groups.



The purpose of this study was to compare ankle dorsiflexion and inversion isometric strength, measures of foot pronation and rearfoot eversion between sedentary women with and without PFPS. There were no differences between groups, thus rejecting the authors’ initial hypothesis. Faulty mechanics at the hip have been correlated with PFPS, particularly excessive femoral adduction and internal rotational. Strengthening of the hip abductor and external rotators is commonly recommended in the management of this disorder. Similarly, faulty mechanics of the foot and ankle distally have been implicated in PFPS including excessive foot pronation and internal tibial rotation resulting in medial femoral rotation and increased patellofemoral stress. It is not surprising that the subjects in this study did not differ in ankle strength from the control group. Piazza stated that when the foot is in a pronated position, the anterior tibialis would present an active restraint to pronation, thereby losing it is function as a rearfoot invertor. Then, one possible reason for the lack of differences between groups in the current study is the fact that the invertor muscles did not lose their function, since the subjects and controls did not differ in relation to foot pronation (as measured using the NDT) or rearfoot eversion. In contrast to the current findings, Barton et al39 inferred that subjects with PFPS would present with greater navicular drop measurement when compared to controls. However, even if a difference had been found in NDT between groups, maybe that would not interfere with isometric strength of the chosen ankle muscles, since Snook did not find a positive correlation between excessive pronation and ankle muscle weakness in healthy population. Some authors have reported that the foot remains pronated when it should already be supinated during closed chain activities such as walking, running and other functional activities in subjects with PFPS, resulting in excessive internal tibial rotation. So, this suggests a possible delay in the activation time of rearfoot inversion during these activities.11,12,41 Many authors have surmised that this inversion occurs due to muscular delayed activation or pre vious muscle fatigue, instead of actual ankle muscle weakness, thus subjects with PFPS may not present with weakness of the inverters and dorsiflexors. Other factors that could be related would be the difference between available ankle range of motion (ROM) and pronation velocity during closed chain activities in subjects with and without PFPS, however these two constructs were not studied in the current research. Another contributor to PFPS may be excessive hip adduction and internal rotation. Fukuda et al35 and Mascal et al34 observed that after a hip abductor and external rotator strengthening program, subjects with PFPS showed significant clinical improvement in terms of function and pain relief. Corroborating these data, some authors demonstrated that an associated 6-week strengthening program focusing on hip abductor and external rotator strengthening, can control the dynamic tibial internal rotation during jogging, thus decreasing the eversion amplitude and the inversion rearfoot moment.42 Some limitations of this study include the method of muscle strength evaluation, due to lack of other evidence regarding ankle muscle isometric dynamometry. Also, handheld dynamometry testing is both examiner- and test-position dependent. However, a pilot study was previously performed by the authors in order to establish reliability, and demonstrated satisfactory to excellent reliability. It is important to highlight that other options for assessment methods of rearfoot eversion could have been used, such as plain film radiographs or motion analysis during a dynamic gait task. However, we chose the NDT and eversion range of motion measures because they are widely used methods in the clinical practice with good to excellent interrater and intrarater reliability for patients with patellofemoral pain syndrome. To the authors’ knowledge, this is the first study focusing on the measurement of isometric ankle muscle strength of the PFPS population. Therefore, future studies are needed to better understand the relationship between such variables as ankle muscle strength and patellofemoral contact area, as well as the possible influence of the timing of muscle activation using electromyography and kinematic assessments of changes during functional activities. Finally, the main clinical implication of this study is that there were no statistical differences in the ankle muscle strength measurements, and measures of foot pronation and rearfoot eversion between PFPS and control groups.


The results of this study indicate that there is no difference in nomalized isometric ankle strength in women with PFPS and those without. When compared to a matched control group, neither the NDT nor the rearfoot eversion measurements were statistically significantly different.

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Non-Operative Rehabilitation for Traumatic and Atraumatic Glenohumeral Instability

Kevin E. Wilk, PT, DPT,a Leonard C. Macrina, MSPT, and Michael M. Reinold, PT, DPT, ATC


Glenohumeral joint instability is a common pathology encountered in the orthopaedic and sports medicine setting. A wide range of symptomatic shoulder instabilities exist ranging from subtle subluxations due to contributing congenital factors to dislocations as a result of a traumatic episode. Non-operative rehabilitation is utilized in patients diagnosed with shoulder instability to regain their previous functional activities through specific strengthening exercises, dynamic stabilization drills, neuromuscular training, proprioception drills, scapular muscle strengthening program and a gradual return to their desired activities. The specific rehabilitation program should be varied based on the type and degree of shoulder instability present and desired level of function. The purpose of this paper is to outline the specific principles associated with non-operative rehabilitation for each of the various types of shoulder instability and to discuss the specific rehabilitation program for each pathology type.

Keywords: Dynamic stabilization, neuromuscular control, shoulder joint


Shoulder instability is a common pathology often seen in the orthopaedic and sports medicine setting. The glenohumeral joint allows tremendous amounts of joint mobility to function, thus, making the joint inherently unstable and the most frequently dislocated joint in the body. Due to the joint’s poor osseous congruency and capsular laxity, it greatly relies on the dynamic stabilizers and neuromuscular system to provide functional stability. Therefore, differentiation between normal translation and pathological instability is often difficult to determine. A wide range of shoulder instabilities exist from subtle subluxations to gross instability. Often the success of the rehabilitation program is based on the recognition and treatment program designed to treat the specific type of instability present. Non-operative rehabilitation is often implemented in patients diagnosed with a variety of shoulder instabilities. These instability patterns can range from congenital multidirectional instabilities to traumatic unidirectional dislocations. We have classified glenohumeral joint instabilities into two broad categories: traumatic and atraumatic. Based on the classification system of glenohumeral instability, as well as several other factors, a non-operative rehabilitation program may be developed. The purpose of this paper is to discuss and overview these factors along with the non-operative rehabilitation programs for the various types of shoulder instability in order to return the patient to their previous level of function.


Seven key factors should be considered when designing a rehabilitation program for a patient with an unstable shoulder (Table). These factors and their significance to the rehabilitation program will be presented.

Onset of Pathology

The first factor to consider in the rehabilitation of a patient with shoulder instability is the onset of the pathology. Pathological shoulder instability may result from an acute, traumatic event or chronic, recurrent instability. The goal of the rehabilitation program may vary greatly based on the onset and mechanism of injury. Following a traumatic subluxation or dislocation, the patient typically presents with significant tissue trauma, pain, and apprehension. The patient who has sustained a dislocation often exhibits more pain due to muscle spasm than a patient who has only subluxed their shoulder. Furthermore, a first-time episode of dislocation is generally more painful than the repeat event. Rehabilitation for the patient with a first-time traumatic episode will be progressed based on the patient’s symptoms with emphasis on early controlled range of motion, reduction of muscle spasms and guarding, and relief of pain. Conversely, a patient presenting with atraumatic instability often presents with a history of repetitive injuries and symptomatic complaints. Often the patient does not complain of a single instability episode but, rather, a feeling of shoulder laxity or an inability to perform specific tasks. Rehabilitation for this patient should focus on early proprioception training, dynamic stabilization drills, neuromuscular control, scapular muscle exercises, and muscle strengthening exercises to enhance dynamic stability due to the unique characteristic of excessive capsular laxity and capsular redundancy in this type of patient.

Degree of Instability

The second factor is the degree of instability present in the patient and the effect on their function. Varying degrees of shoulder instability exist such as a subtle subluxation or gross instability. The term subluxation refers to the complete separation of the articular surfaces with spontaneous reduction. Conversely, a dislocation is a complete separation of the articular surfaces and requires a specific movement or manual reduction to relocate the joint, resulting in underlying capsular tissue trauma. The degree of trauma to the soft tissue of the glenohumeral joint with a shoulder subluxation is can be quite extensive. Speer et al has reported that in order for a shoulder dislocation to occur, a Bankart lesion and soft tissue trauma must be present on both sides of the glenohumeral joint capsule. Thus, in the situation of an acute traumatic dislocation, the anterior capsule may be avulsed off the glenoid (Bankart lesion) and the posterior capsule may be stretched, allowing the humeral head to dislocate. Warren et al4 refer to this damage to both the anterior and posterior capsule as the “circle stability concept.” The rate of progression of the rehabilitation program will vary based upon the degree of instability and persistence of symptoms. For example, a patient with mild subluxations and muscle guarding may initially tolerate strengthening exercises and neuromuscular control drills more than a patient with a significant amount of muscular guarding.

Frequency of Dislocation

The next factor to influence the rehabilitation program is the frequency of dislocation or subluxation. The primary traumatic dislocation is most often treated conservatively with immobilization in a sling and early controlled passive range of motion (ROM) exercises, especially with first time dislocations. The incidence of recurrent dislocation ranges from 17-96% with a mean of 67% in patient populations between the ages of 21-30 years old. Therefore, the rehabilitation program should progress cautiously in young athletic individuals. It should be noted that Hovelius et al has demonstrated that the rate of recurrent dislocations is based on the patient’s age and not affected by the length of post-injury immobilization. Individuals between the ages of 19 and 29 years are the most likely to experience multiple episodes of instability. Hovelius et al noted patients in their 20’s exhibited a recurrence rate of 60%, whereas, patients in their 30′s to 40′s had less than a 20% recurrence rate. In adolescents, the recurrence rate is as high as 92% and 100% with an open physes. Chronic subluxations, as seen in the atraumatic, unstable shoulder may be treated more aggressively due to the lack of acute tissue damage and less muscular guarding and inflammation. Rotator cuff and periscapular strengthening activities should be initiated while ROM exercises are progressed. Caution is placed on avoiding excessive stretching of the joint capsule through aggressive ROM activities. The goal is to enhance strength, proprioception, dynamic stability and neuromuscular control, especially in the specific points of motion or direction which results in instability complaints.

Direction of Instability

The fourth factor is the direction of instability present. The three most common forms include anterior, posterior, and multidirectional. Anterior instability is the most common traumatic type of instability seen in the general orthopaedic population, representing approximately 95% of all traumatic shoulder instabilities. Following a traumatic event in which the humeral head is forced into extremes of abduction and external rotation, or horizontal abduction, the glenolabral complex and capsule may become detached from the glenoid rim resulting in anterior instability. This type of detachment is referred to a Bankart lesion. (Figure 1) Baker et al have identified four types of Bankart lesions based on the size and the degree of tissue involvement. Conversely, rarely will a patient with atraumatic instability due to capsular redundancy dislocate their shoulder. It is the author’s opinion that these patients are more likely to repeatedly sublux the joint without complete separation of the humerus from the glenoid rim. Capsular avulsions can occur on the glenoid side (Bankart lesion) or on the humeral head side referred to as a HAGL lesion (humeral avulsion of the inferior glenohumeral ligament). Posterior instability occurs less frequently, only accounting for less than 5% of traumatic shoulder dislocations. This type of instability is often seen following a traumatic event such as falling onto an outstretched hand or from a pushing mechanism. However, patients with significant atraumatic laxity may complain of posterior instability especially with shoulder elevation, horizontal adduction and excessive internal rotation due to the strain placed on the posterior capsule in these positions. In professional or collegiate football, the incidence of posterior shoulder instability appears higher than the general population. This is especially true in linemen. Mair et al reported on nine athletes with posterior instability in which eight of nine were linemen and seven were offensive linemen. Often, these patients require surgery as Mair et al also reported 75% required surgical stabilization. Kaplan et al reported in a study of collegiate football players that 78% required surgical stabilization. Multidirectional instability (MDI) can be identified as shoulder instability in more than one plane of motion. Patients with MDI have a congenital predisposition and exhibit ligamentous laxity due to excessive collagen elasticity of the capsule. Furthermore, Rodeo et al reported that this type of patient turns over collagen at a faster rate. The authors consider an inferior displacement of greater than 8-10mm during the sulcus maneuver (Figure 2) with the arm adducted to the side as significant hypermobility, thus suggesting significant congenital laxity. Due to the atraumatic mechanism and lack of acute tissue damage, ROM is often normal to excessive. Patients with recurrent shoulder instability due to MDI generally have weakness in the rotator cuff, deltoid muscle, and scapular stabilizers with poor dynamic stabilization and inadequate static stabilizers. Initially, the focus of the rehabilitation program is on maximizing dynamic stability, scapula positioning, proprioception, and improving neuromuscular control in mid ROM. Also, rehabilitation should focus on improving the efficiency and effectiveness of glenohumeral joint force couples through co-contraction exercises, rhythmic stabilization, and neuromuscular control drills. Isotonic strengthening exercises for the rotator cuff, deltoid muscle, and scapular muscles are also emphasized to enhance dynamic stability. Morris et al reported the EMG activity of the rotator cuff and deltoid muscle in MDI and asymptomatic subjects. The authors noted the most significant difference was in the deltoid muscles compared to the rotator cuff muscles in their groups.

Concomitant Pathologies

The fifth factor involves considering other tissues that may have been affected and the premorbid status of the tissue. Disruption of the anterior capsulolabral complex from the glenoid commonly occurs during a traumatic injury resulting in an anterior Bankart lesion. Often osseous lesions may be present such as a concomitant Hill Sach’s lesion caused by an impaction of the postero-lateral aspect of the humeral head as it compresses against the anterior glenoid rim during relocation. This Hill Sach’s lesion has been reported in up to 80% of dislocations. Conversely, a reverse Hill Sach’s lesion may be present on the anterior aspect of the humeral head due to a posterior dislocation. Occasionally, a bone bruise may be present in individuals who have sustained a shoulder dislocation as well as pathology to the rotator cuff. In rare cases of extreme trauma, the brachial plexus may become involved as well. Other common injuries in the unstable shoulder may involve the superior labrum (SLAP lesion) such as a type V SLAP lesion characterized by a Bankart lesion of the anterior capsule extending into the anterior superior labrum. These concomitant lesions may significantly slow down the rehabilitation program in order to protect the healing tissue.

Neuromuscular Control

The sixth factor to consider is the patient’s level of neuromuscular control, particularly at end range. Neuromuscular control may be defined as the efferent, or motor, output in reaction to an afferent, or sensory input. The afferent input is the ability to detect the glenohumeral joint position and motion in space with resultant efferent response by the dynamic stabilizers as they blend with the joint capsule to assist in stabilization of the humeral head. Injury with resultant insufficient neuromuscular control could result in deleterious effects to the patient. As a result, the humeral head may not center itself within the glenoid, thereby, compromising the surrounding static stabilizers. The patient with poor neuromuscular control may exhibit excessive humeral head migration with the potential for injury, an inflammatory response, and reflexive inhibition of the dynamic stabilizers. Several authors have reported that neuromuscular control of the glenohumeral joint may be negatively affected by joint instability. Lephart et al compared the ability to detect passive motion and the ability to reproduce joint positions in patients with normal, unstable, and surgically repaired shoulders. The authors reported a significant decrease in proprioception and kinesthesia in the shoulders with instability when compared to both normal shoulders and shoulders undergoing surgical stabilization procedures. Smith and Brunoli reported a significant decrease in proprioception following a shoulder dislocation. Blasier et al reported that individuals with significant capsular laxity exhibited a decrease in proprioception compared to patients with normal laxity. Zuckerman et al noted that proprioception is affected by the patient’s age with older subjects exhibiting diminished proprioception than a comparably younger population. Thus, the patient presenting with traumatic or acquired instability may present with poor neuromuscular control.

Activity Level

The final factor to consider in the non-operative rehabilitation of the unstable shoulder is the arm dominance and the desired activity level of the patient. If the patient frequently performs an overhead motion or sporting activities such as a tennis, volleyball, or a throwing sport, then the rehabilitation program should include sport specific dynamic stabilization exercises, neuromuscular control drills, and plyometric exercises in the overhead position once full, pain free ROM and adequate strength has been achieved. Patients whose functional demands involve below shoulder level activities will follow a progressive exercise program to return full ROM and strength. The success rates of patients returning to overhead sports after a traumatic dislocation of their dominant arm are extremely low. Arm dominance can also significantly influence the successful outcome. The recurrence rates of instabilities vary based on age, activity level, and arm dominance. In athletes involved in collision sports, the recurrence rates have been reported collision sports, the recurrence rates have been reported between 86-94%.


Patients may be classified into two common forms of shoulder instability – traumatic and atraumatic. Specific guidelines to consider in the rehabilitation of each patient population will be outlined. A four-phase rehabilitation program will be discussed for traumatic shoulder instability, followed by an overview of variations and key rehabilitation principles for atraumatic shoulder instability (congenital and acquired laxity).

Traumatic Shoulder Instability

Phase I-Acute Phase

Following a first time traumatic shoulder dislocation or subluxation, the patient often presents in considerable pain, muscle spasm, and an acute inflammatory response. The patient usually self-limits their motion by guarding the injured extremity in an internally rotated and adducted position against the side of their body to protect the injured shoulder. The goals of the acute phase are to 1) diminish pain, inflammation, and muscle guarding 2) promote and protect healing soft tissues, 3) prevent the negative effects of immobilization, 4) re-establish baseline dynamic joint stability, and 5) prevent further damage to glenohumeral joint capsule. (Appendix 1)

Immediate limited and controlled motion is allowed following a traumatic dislocation in patients between the ages of 18-28 years but immobilize patients between the ages of 29-54 years old. However, motion is restricted so as to not to cause further tissue attenuation. A short period of immobilization in a sling to control pain and to allow scar tissue to form for enhanced stability may be necessary for 7-14 days although no long-term benefits regarding recurrence rates and immobilization have been made in younger patients between the ages of 18-28 years old. Individuals above the age of 28 are usually immobilized for 2-4 weeks to allow scarring of the injured capsule. Potential complications with immobilization may include a decrease in joint proprioception, muscle disuse and atrophy, and a loss of ROM in specific age groups. Therefore, prolonged use of immobilization following a traumatic dislocation may not be recommended in all patients. The ideal position to immobilize the glenohumeral has traditionally been in internal rotation with the arm close to the body. Recent studies by Itoi et al examined positional differences of immobilization and compared the rates of recurrent dislocations. The authors concluded that immobilization in external rotation significantly reduced the recurrence rate of instability in chronic and first-time dislocators. Itoi et al has recommended immobilization with the arm in 30 degrees of abduction and external rotation, compared to a group of patients immobilized in internal rotation. The results indicated a 0% recurrence rate in external rotation and 30% incidence of instability in the group immobilized in internal rotation. The authors stated that the resultant Bankart lesion had improved coaptation to the glenoid rim with immobilization in external rotation versus conventional immobilization in a sling. Passive ROM is initiated in a restricted and protected range based on the patient’s symptoms. The early motion is intended to promote healing, enhance collagen organization, stimulate joint mechanoreceptors, and aid in decreasing the patient’s pain through neuromuscular modulation. Painfree active-assisted ROM exercises such as pendulums and external/internal rotation at 45 degrees of abduction using an L-bar (Breg Corp. Vista, CA) may also be initiated. Passive ROM exercises are also performed in a painfree arc of motion. Modalities such as ice, transcutaneous electrical nerve stimulation (TENS), and high voltage stimulation may also be beneficial to decrease pain, inflammation, and muscle guarding. Strengthening exercises are initially performed through submaximal, painfree isometric contractions to initiate muscle recruitment and retard muscle atrophy. Electrical stimulation of the posterior cuff musculature may also be incorporated to enhance the muscle fiber recruitment process early on in the rehabilitation process and also in the next phase when the patient initiates iso-tonic strengthening activities. (Figure 3) Reinold et al believe that the use of electrical stimulation may improve force production of the rotator cuff particularly the external rotators immediately after an acute injury. Dynamic stabilization exercises are also performed to re-establish dynamic joint stability. The patient maintains a static position as the rehabilitation specialist performs manual rhythmic stabilization drills to facilitate muscular co-contractions. These manual rhythmic stabilization drills are performed for the shoulder internal and external rotators in the scapular plane at 30 degrees of abduction and are performed at painfree angles which do not compromise the healing capsule. Rhythmic stabilization for flexion and extension may also be performed with the shoulder at 100 degrees of flexion and 10 degrees of horizontal abduction. Strengthening exercises are also performed for the scapular retractors and depressors to reposition the scapula in its proper position. Scapula strengthening is critical for successful rehabilitation. Closed kinetic chain exercises such as weight shifting on a ball are performed to produce a co-contraction of the surrounding glenohumeral musculature and to facilitate joint mechanoreceptors to enhance proprioception. Weight shifts are usually able to be performed immediately following the injury unless posterior instability is present.

Phase II-Intermediate phase

During the intermediate phase, the program emphasizes regaining full ROM along with progressing strengthening exercises of the rotator cuff, and re-establishing muscular balance of the glenohumeral joint, scapular stabilizers, and surrounding shoulder muscles. Before the patient enters Phase II, certain criteria must be met which include diminished pain and inflammation, satisfactory static stability, and adequate neuromuscular control. To achieve the desired goals of this phase, passive ROM is performed to the patient’s tolerance with the goal of attaining nearly full ROM. Active-assisted ROM exercises using a rope and pulley along with flexion and external/internal rotation exercises at 90 degrees of abduction using an L-bar may be progressed to tolerance without stressing the involved tissues. External rotation at 90 degrees of abduction is generally limited to 65-70 degrees to avoid overstressing the healing anterior capsuloligamentous structures for approximately 4-8 weeks but eventually increasing ROM to full motion as the patient tolerates. Isotonic strengthening exercises are also initiated during this phase. Emphasis is placed on increasing the strength of the internal and external rotators and scapular muscles to maximize dynamic stability. The ultimate goal of the strengthening phase is to re-establish muscular balance following the injury. Kibler1noted that scapular position and strength deficits have been shown to contribute to glenohumeral joint instability. Exercises initially include external and internal rotation with exercise tubing at 0 degrees of abduction along with sidelying external rotation and prone rowing. During the latter part of this phase, isotonic exercises are progressed to emphasize rotator cuff and scapulothoracic muscle strength. Manual resistive exercises such as sidelying external rotation and prone rowing may also prove beneficial by having the clinician vary the resistance throughout the ROM. Incorporating manual concentric and eccentric manual exercises and rhythmic stabilization drills at end range to enhance neuromuscular control and dynamic stability is also recommended. (Figure 4)

Closed kinetic chain exercises are progressed to include a hand on the wall stabilization drills in the plane of the scapular at shoulder height as the patient tolerates. (Figure 5) Push-ups are performed first with hands on a table then progressed to a push-up on a ball or unstable surface while the rehabilitation specialist performs rhythmic stabilization to the involved and uninvolved upper extremity along with the trunk to integrate dynamic stability and core strengthening (tilt board, ball, etc.). (Figure 6) Caution should be placed while performing closed kinetic chain exercises in patients with posterior instability for 6-8 weeks at allow for adequate healing and strength gains. Furthermore, patients with significant scapular winging should perform push-ups until adequate scapular strength is accomplished. Core stabilization drills should also be performed to enhance scapular control. Additionally, strengthening exercises may be advanced in regards to resistance, repetitions, and sets as the patient improves. End range rhythmic stabilization drills with the arm at 0 degrees of adduction or at 45 degrees of abduction are also performed. Exercises such as tubing with manual resistance and end range rhythmic stabilization drills are also performed. (Figure 7) The goal of these exercise drills is to improve proprioception and neuromuscular control at end range.

Phase III- Advanced Strengthening

In the advanced strengthening phase, the focus is on improving strength, dynamic stability, and neuromuscular control near end range through a series of progressive strengthening exercises for a gradual return to the patient’s activity. Criteria to enter this phase include: 1) minimal pain and tenderness, 2) full range of motion, 3) symmetrical capsular mobility, 4) good (at least ⅘ manual muscle test) strength, endurance and dynamic stability of the scapulothoracic and upper extremity musculature. Muscle fatigue has also been associated with a decrease in neuromuscular control. Carpenter et al observed the ability to detect passive motion of shoulders positioned at 90 degrees of abduction and 90 degrees of external rotation. The investigators reported a decrease in both the detection of external and internal rotation movement following an isokinetic fatigue protocol. Therefore, exercises designed to enhance endurance in the upper extremity such as using low resistance and high repetitions (20-30 repetitions per set) are incorporated during this phase. Also, exercise sets utilizing time may be incorporated, such as 30 second or 60 second exercise bouts. These exercises may include tubing external and internal rotation, plyoball wall dribbling, and submaximal manual resistance drills. Aggressive upper body strengthening through the continuation of a progressive isotonic resistance program is recommended. A gradual increase in resistance as well as a progression to a more functional position by performing tubing exercises at 90 degrees of abduction to strengthen the external and internal rotators is also recommended. Additionally, more aggressive isotonic strengthening exercises such as bench press, seated row, and latissimus pull-downs may be incorporated in a protected range of motion during this phase. During bench press and seated rows, the patient is instructed to not extend the upper extremities beyond the plane of the body to minimize stress on the shoulder capsule. Latissimus pulldowns are performed in front of the head and the patient is instructed to avoid full extension of the arms to minimize the amount of traction force applied to the shoulder joint. Also during this phase, the patient continues to perform rhythmic stabilization drills with the rehabilitation specialist and gradually progresses to a position of apprehension utilizing tubing at 90 degrees of abduction with end range rhythmic stabilization drills to enhance dynamic stability. A patient wishing to return to athletic participation may be instructed to perform plyometric exercises for the upper extremity. These activities are incorporated to regain any remaining functional ROM as well as improving neuromuscular control and to train the extremity to produce and dissipate forces. Initially, 2-handed drills close to the body such as chest pass, side-to-side and overhead soccer throws (Figure 8) using a 3-5 pound medicine ball may be performed to enhance dynamic stabilization of the glenohumeral joint. Exercises are initiated with 2-hand drills close to the center of gravity and gradually progressed to longer lever arms away from the patient’s body. Drills are progressed to challenge the dynamic stabilizers of the shoulder. After approximately two weeks of pain free 2-handed drills, the athlete progresses to 1-handed plyometric drills using a small medicine ball (1-2 lbs) and throwing into a plyoback. Plyoball wall dribbles in the 90/90 position (Figure 9) to improve overhead muscle endurance may also be incorporated.

Phase IV- Return to Activity Phase

In the return to activity phase, the goal is to increase, gradually and progressively, the functional demands on the shoulder in order for the patient to return to unrestricted, sport or daily activities. Other goals of this phase are to maintain the patient’s muscular strength and endurance, dynamic stability and functional range of motion. The criteria to progress into this phase include: 1) full functional ROM, 2) adequate static stability, 3) satisfactory muscular strength and endurance, 4) adequate dynamic stability, and 5) a satisfactory clinical exam. The general orthopaedic patient continues to perform a maintenance program to improve strength, dynamic stability, and neuromuscular control as well as maintaining full, functional and painfree ROM. The athlete continues to perform aggressive strengthening exercises such as plyometrics, proprioceptive neuromuscular facilitation drills, and isotonic strengthening. In addition, the athlete may begin functional sport activities through an interval return to sport program. These activities are designed to gradually return motion, function, and confidence in the upper extremity by progressing through graduated sport-specific activities. These interval sport programs are set up to minimize the chance of re-injury while training the patient for the demands of each individual sport. Each program should be individualized based on the patient’s injury, skill level, and goals. The duration of each program is based on several factors including the extent of the injury, the sport and level of play, along with the time of season. The athlete is allowed to return to unrestricted sports activities after completion of an appropriately designed rehabilitation program and a successful clinical exam including full ROM, strength along with adequate dynamic stability and neuro-muscular control. We routinely perform a combination of isokinetic testing for our overhead athletes, which we refer to as the “Thrower’s Series.” Criteria to begin an interval sport program includes an external rotation/internal rotation strength ratio of 66-76% or higher at 180°/second, an external rotation to abduction ratio of 67-75% or higher at 180°/second. Patients returning to contact sports such as hockey, football, rugby, etc may be required to wear a shoulder stability brace (Don-Joy) for the initiation of the sport return. (Figure 10)

Rehabilitation for Atraumatic Shoulder Instability

Rehabilitation of the patient with congenital shoulder instability poses a significant challenge for the rehabilitation specialist. The patient typically presents with several episodes of instability which limits them from performing certain tasks which may include daily work tasks as well as recreational or sports activities. This type of instability may arise from several factors including excessive redundancy and capsular laxity, poor osseous configuration such as a flattened glenoid fossa, or weakness in the glenohumeral and scapular musculature resulting in poor neuromuscular control. Any of these factors, individually or in combination, may contribute to pathological glenohumeral instability. The focus of the rehabilitation program for the patient with atraumatic instability is similar to the traumatically unstable shoulder, however, this program involves a slower progression with careful consideration to avoid excessive stretching to the capsular tissue. Furthermore, early goals include improving proprioception, dynamic stability, neuromuscular control, and scapular muscle strengthening to gradually return the patient to functional activities without limitations. As previously mentioned, the early phase of rehabilitation involves reducing shoulder pain and muscular inhibition while abstaining from activities that cause apprehension. Shoulder muscle activation has been shown to differ in patients with congenital laxity versus in a normal, stable shoulder. Normal force coupling that exists to dynamically stabilize the glenohumeral joint is altered resulting in excessive humeral head migration and a feeling of subluxation by the patient. Rockwood and Burkhead found that an exercise program was effective in the management of 80% of atraumatic instability. A recent study by Misamore et al found improved results in 49% (28 of 59) of patients in a long term follow up study of atraumatic, athletic patients. The rehabilitation program (Appendix 2) for the patient with atraumatic instability involves regaining full ROM without excessive stress to the involved tissues. The patient often presents with excessive ROM, therefore, passive ROM activities are not the focus of the rehabilitation program. Special attention is placed to avoid excessive stretches to the involved tissues. Modalities such as cryotherapy, phonophoresis, high voltage stimulation, and TENS may be used to minimize pain and inflammation. The reduction of shoulder pain may also be accomplished through gentle motion activities to neuromodulate pain, NSAIDs prescribed by the physician and abstaining from painful arcs of active and passive ROM. The focus of the early phase of the rehabilitation program is to minimize any further muscle atrophy and reflexive inhibition resulting from disuse, repeated subluxation episodes, and pain. Isometric contraction exercises may be performed for the glenohumeral muscles particularly the rotator cuff. Rhythmic stabilization drills may also be performed to facilitate a muscular co-contraction/co-activation to improve neuromuscular control and enhance the sensitivity of the afferent mechanoreceptors. (Figure 11) The goal is to create a more efficient agonist/antagonist co-contraction to improve force coupling and joint stability during active movements. The authors of this paper believe that exercises such as rhythmic stabilization drills and closed kinetic chain exercises to promote a co-contraction and an improvement in proprioception are beneficial for this patient population. Axial compression exercises are progressed from standing weight shifts on a table top to then include the quadruped and tripod positions (Note – this position should be avoided if posterior instability is present). Rhythmic stabilization of the involved extremity as well as at the core and trunk may be applied during these closed kinetic chain drills to further challenge the patient’s dynamic stability and neuromuscular control. Unstable surfaces such as tilt boards, foam, large exercise balls, and the Biodex stability system (Biodex Corp., Shirley, NY) may be incorporated to further challenge the patient’s dynamic stability while in the closed chain position to further promote a co-activation or cocontraction of the surrounding musculature. (Figure 12)

Patients with congenital laxity often present with significant rotator cuff and scapular strength deficits, particularly the external rotators, scapular retractors, and scapular depressors. A progressive isotonic strengthening program may be initiated to improve rotator cuff and scapular musculature strength, endurance, and dynamic stability. Proper scapula stability and movement is vital for asymptomatic function. Scapula strengthening will improve proximal stability and therefore enable distal segment mobility for during the patient’s functional tasks. These exercises may include external rotation at 0 degrees of abduction, sidelying external rotation, standing external rotation at 90 degrees of abduction, prone external rotation, prone rowing, prone extension and prone horizontal abduction at 100 degrees with external rotation. Other scapular training exercises commonly incorporated include supine serratus punches and a dynamic hug for serratus anterior strengthening. Bilateral external rotation with scapular retraction and table lifts may also be performed to strengthen the lower trapezius. Neuromuscular control drills are performed for the scapular musculature by having the rehabilitation specialist manually resist scapula movements. The goal of these drills is to enhance strength, endurance, and scapula proprioception. The function of neuromuscular control system must not be overlooked in this patient population. Functional exercise drills that include positions of instability to induce a reflexive muscular response may protect against future injury or recurring episodes of instability. Active joint repositioning tasks, proprioceptive neuromuscular facilitation (PNF) and plyometric exercises may be beneficial as well to evoke a neuromuscular response. Once sufficient strength of the scapular stabilizers and posterior cuff has been achieved, the patient is encouraged to use the shoulder only in the most stable positions; those in the plane of the scapular during humeral elevation. Activities that promote a feeling of joint instability with or without subluxation or dislocation should be avoided. Only when coordination and confidence are achieved through progressive strengthening should the patient attempt activities in an intrinsically unstable position. Bracing of the glenohumeral joint for return to sporting activities may also be necessary to provide immobilization or controlled ROM to protect against further injury. The primary focus of the rehabilitation program for the congenitally unstable shoulder patient is to enhance strength and balance in the rotator cuff, improve scapular position and core stability, along with improved proprioception and neuromuscular control. Once symptoms have subsided and sufficient strength has been achieved, the patient may resume normal shoulder function, which may include sport activities.


The glenohumeral joint is an inherently unstable joint that relies on the interaction of the dynamic and static stabilizers to maintain stability. Disruption of this interplay or poor development of any of these factors may result in instability, pain, and a loss of function. Rehabilitation will vary based on the type of instability present and the key principles described. A comprehensive program designed to establish full range of motion, balance capsular mobility, along with maximizing muscular strength, endurance, proprioception, dynamic stability and neuromuscular control is essential. A functional approach to rehabilitation using movement patterns and sport specific positions along with an interval sport program will allow a gradual return to athletics. The focus of the program should minimize the risk of re-injury and ensure that the patient can safely produce and dissipate forces at the glenohumeral joint.

Stabilization exercise compared to general exercises or manual therapy for the management of low back pain: A systematic review and meta-analysis

Mansueto Gomes-Neto, Jordana Moura Lopes, Cristiano Sena Conceição, Anderson Araujo, Alécio Brasileiro e, Camila Sousa, Vitor Oliveira Carvalho e Fabio Luciano Arcanjo.

1. Background: Low back pain (LBP) is a multifactorial disorder with a high prevalence; most people experience back pain at some point in their life and it has a significant impact on individuals, their families, and the healthcare systems. This disorder causes disability, participation restriction, a career burden, the use of health-care resources, and a financial burden. In addition to medical treatment, musculoskeletal physiotherapy (exercise therapy and manual therapy) is the most common method of conservative intervention for LBP (Amit, Manish, & Taruna, 2013; Hoy, Brooks, Blyth, & Buchbinder, 2010; Smith et al., 2014). The European Guidelines for Management of Chronic Non-Specific Low Back Pain (Airaksinen et al., 2006) recommend supervised exercise therapy as the first-line treatment. Stabilization exercise programs have become widely used for low back rehabilitation because of its effectiveness in some aspects related to pain and disability (Ferreira, Ferreira, Maher, Herbert, & Refshauge, 2006; Liddle, David Baxter, & Gracey, 2009). Stabilization exercise are exercise interventions that aim to improve function of specific trunk muscles thought to control inter-segmental movement of the spine and enable the patient to regain control and coordination of the spine and pelvis using principles of motor learning such as segmentation and simplification (Hodges and Richardson, 1996; Richardson, Jull, Hides, & Hodges, 1999). Although stabilization exercises have become the major focus in spinal rehabilitation, as well as in prophylactic care, the therapeutic evidence using pain and disability control variables as outcomes remains controversial. Most therapeutic studies have compared stabilization exercise, general exercise, and manual therapy. Systematic reviews to date that have evaluated the effectiveness of exercise therapies have concluded that there is no evidence to support the superiority of one form of exercise over another (Ferreira et al., 2006; Macedo et al., 2010). In a recent review, Wang et al. (Wang et al., 2012) showed that stability exercise is more effective for decreasing pain than general exercise, and it may improve physical function in patients with chronic LBP. However, the efficacy of stability exercise was not compared with manual therapy. After reviews on this topic were published (Ferreira et al., 2006; Macedo et al., 2010; Wang et al., 2012), new randomized controlled trials (RCTs) have been released (Amit et al., 2013; Inani and Selkar, 2013; Macedo et al., 2012; Sung, 2013). The Cochrane Collaboration recommends that systematic reviews be updated biannually (Higgins and Green, 2006). Moreover, as far as we know, no meta-analysis has been performed on studies comparing segmental stabilization exercise with manual therapy. The meta-analysis technique minimizes subjectivity by standardizing treatment effects of relevant studies into effect sizes (ESs), pooling, and analyzing data to draw conclusions. The aim of this systematic review with meta-analysis was to analyze published RCTs that investigated the efficacy of stabilization exercises versus general exercises or manual therapy in patients with LBP.

2. Methods: This review was planned and performed in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines (Moher et al., 2009).

2.1. Eligibility criteria: This systematic review included all RCTs that investigated the efficacy of stabilization exercises in patients with non-specific LBP. Studies that compared a stabilization exercises group with a general exercises group or a stabilization exercises group with a manual therapy group were included. Studies were considered for inclusion regardless of publication status, language, or size. Trials that enrolled patients with chronic non-specific LBP were included in this meta-analysis. For this study was considered the chronic nonspecific LBP as low back pain (>3 months’ duration) without leg pain. The studies that enrolled patients with acute LBP in association with neurologic diseases were excluded from this systematic review. The main outcomes of interest were pain (assessed using visual analog scale, numerical rating scale, or any other instrument or scale) with scores ranging from 0 to 10, disability, and function assessed by any questionnaire. To be eligible, the RCTs should have randomized patients with chronic LBP to at least one group of stabilization exercises. For this review, stabilization exercises was considered as prescribed exercises aimed at improving function of specific trunk muscles that control inter-segmental movement of the spine, including the transversus abdominis, multifidus, diaphragm, and pelvic floor muscles (Hodges and Richardson, 1996; Richardson et al., 1999). General exercise were prescribed exercises that included strengthening and/or stretching exercises for the main muscle groups of the body as well as exercises for cardiovascular fitness. Manual therapy comprised physiotherapy based on manual techniques (joint mobilization or manipulation techniques).

2.2. Search methods for identification of studies: We searched for studies on MEDLINE, LILACS, EMBASE, SciELO, Cumulative Index to Nursing and Allied Health (CINAHL), PEDro, and the Cochrane Library, up to November 2014, without language restrictions. A standard protocol for this search was developed and whenever possible, a controlled vocabulary was used (Mesh terms for MEDLINE and Cochrane; EMTREE for EMBASE). Keywords and their synonyms were used to sensitize the search. For identification of RCTs in PUBMED, the optimally sensitive strategy developed for the Cochrane Collaboration was used (Higgins and Green, 2006). For identification of RCTs in EMBASE, a search strategy using similar terms was adopted. In the search strategy, there were four groups of keywords: study design, participants, interventions, and outcome measures. We analyzed the reference lists of all eligible articles in order to detect other potentially eligible studies. For ongoing studies or when any data was to be confirmed or additional information was needed, the authors were contacted by e-mail. The previously described search strategy was used to obtain titles and abstracts of studies that were relevant for this review. Each identified abstract was independently evaluated by two authors. If at least one of the authors considered one reference eligible, the full text was obtained for complete assessment. Two reviewers independently assessed the full text of selected articles to verify if they met the criteria for inclusion or exclusion. In case of any disagreement, the authors discussed the reasons for their decisions and a consensus was reached. Two authors, independently blinded, extracted descriptive and outcome data from the included studies using a standardized form developed by the authors and adapted from the Cochrane Collaboration’s (Higgins and Green, 2006) model for data extraction. We considered: 1) aspects of the study population, such as the average age and sex; 2) aspects of the intervention performed (sample size, type of stabilization exercise performed, presence of supervision, frequency, and duration of each session); 3) follow-up (if the patients included were analyzed); 4) loss to follow-up (if there was a loss in the sample); 5) outcome measures; and 6) presented results. Another author resolved disagreements. Any additional information required from the original author was requested by e-mail. The risk of bias of included studies was assessed independently by two authors using The Cochrane Collaboration’s “Risk of bias” tool (Higgins and Green, 2006). The following criteria were assessed: Random sequence generation, allocation concealment, blinding of participants and personnel, blinding of outcome assessment, incomplete outcome data, selective reporting, intention-to-treat analysis, and completeness of follow-up. The quality of evidence was independently scored by two researchers based on the PEDro scale (Olivo et al., 2008) that consisted of 11 items based on a Delphi list (Verhagen et al., 1998). The PEDro scale is a useful tool for assessing the quality of physical therapy and rehabilitation trials (Olivo et al., 2008). One item on the PEDro scale (eligibility criteria) is related to external validity and is generally not used to calculate the method score, leaving a score range of 0e10 (Maher, Sherrington, Herbert, Moseley, & Elkins, 2003).

2.3. Statistical assessment: Pooled-effect estimates were obtained by comparing the least square mean percentage change from the baseline to the study end for each group, and were expressed as the weighted mean difference between groups. Calculations were performed using a random-effects model. Two comparisons were made: stabilization exercises group versus general exercises group and stabilization exercises group versus manual therapy group. An a value of 0.05 was considered significant. Statistical heterogeneity of the treatment effect among studies was assessed using Cochran’s Q-test and the inconsistency I (Hoy et al., 2010) test, in which values between 25% and 50% were considered indicative of moderate heterogeneity, and values > 50% were considered indicative of high heterogeneity (Higgins, Thompson, Deeks, & Altman, 2003). All analyses were conducted using Review Manager Version 5.0 (Cochrane Collaboration). (CollaborationAvailab).

3. Results: The initial search led to the identification of 653 abstracts, from which 24 studies were considered as potentially relevant and were retrieved for detailed analysis. After complete reading of 24 articles, 13 were excluded. Finally, 11 papers (Akbari, Khorashadizadeh, & Abdi, 2008; Amit et al., 2013; Ferreira et al., 2007; França, Burke, Hanada, & Marques, 2010, 2012; Goldby, Moore, & Doust, 2006; Inani and Selkar, 2013; Macedo et al., 2012; Rasmussen-Barr, Nilsson-Wikmar, & Arvidsson, 2003; Sung, 2013; Unsgaard-Tøndel, Fladmark, Salvesen, & Vasseljen, 2010) met the eligibility criteria. Fig. 1 shows the PRISMA flow diagram of studies for this review. Each of the papers was scored using the PEDro scale. Table 1 presents the results of individual assessment by the PEDro scale. The final sample ranged from 30 to 172 participants, and the mean age ranged from 59 to 67 years. All studies analyzed in this review included outpatients with documented LBP. The parameters used in the application of stabilization exercises have been reported, and all studies described the progressive nature of the programs. The duration of stabilization exercises programs ranged from 4 to 12 weeks. The duration of sessions varied from 20 to 60 min in the studies. The frequency of sessions ranged from one to three times per week. Table 2 summarizes the characteristics of included studies.

3.1. Pain intensity: In total, eight trials assessed pain intensity (Akbari et al., 2008; Amit et al., 2013; Ferreira et al., 2007; França et al., 2010; Goldby et al., 2006; Macedo et al., 2012; Rasmussen-Barr et al., 2003; Sung, 2013). The meta-analyses showed (Fig. 2) a significant improvement in pain of 1.03 (95% CI: 1.79 to 0.27, N ¼ 603) for participants in the stabilization exercises group compared to the general exercises group. Three studies compared stabilization exercise to manual therapy (Ferreira et al., 2007; Goldby et al., 2006; Rasmussen-Barr et al., 2003). A non-significant difference in pain of 0.38 (95% CI: 0.98 to 0.22, N ¼ 358; Fig. 3) was noted for participants in the stabilization exercises group compared to the manual therapy group. Age mean.




3.2. Disability: Seven trials assessed disability (Ferreira et al., 2007; França et al., 2010, 2012; Inani and Selkar, 2013; Macedo et al., 2012; Sung, 2013; Unsgaard-Tøndel et al., 2010). Five of these studies measured disability using the Oswestry Disability Index (França et al., 2010, 2012; Inani and Selkar, 2013; Sung, 2013; Unsgaard- Tøndel et al., 2010), and two assessed disability using the Roland-Morris Disability Questionnaire (Ferreira et al., 2007; Macedo et al., 2012). In four individual trials, significant improvements were found in the stabilization exercises group compared to the general exercises group as measured by the Oswestry Disability Index. The meta-analyses showed a significant improvement in disability of 5.41 (95% CI: 8.34 to 2.49, N ¼ 209; Fig. 4) for participants in the stabilization exercises group compared to the general exercises group. As assessed using the Roland-Morris Disability Questionnaire, the non-significant difference in disability of 0.75 (95% CI: 2.26 to 0.75, N ¼ 310; Fig. 5) was noted for participants in the stabilization exercises group compared to the general exercises group. Three studies compared stabilization exercise to manual therapy (Ferreira et al., 2007; Goldby et al., 2006; Rasmussen-Barr et al., 2003). A non-significant difference in disability of 0.17 (95% CI: 0.38 to 0.03, N ¼ 358) was found for participants in the stabilization exercises group compared with manual therapy (Ferreira et al., 2007; Goldby et al., 2006; Rasmussen-Barr et al., 2003). (Fig. 6) Owing to the differences between instruments used to measure disability (stabilization exercises group versus manual therapy group), a meta-analysis was performed using the standardized mean difference. All studies included patients of both genders, but there was an overall predominance of female. The mean age ranged from 38 (Rasmussen-Barr et al., 2003) to 53 (Ferreira et al., 2007) years. All studies analyzed in this review included outpatients with documented chronic nonspecific LBP (pain duration > 12 weeks). The parameters used in the application of manual therapy have been reported. The duration of manual therapy programs ranged from 8 (Ferreira et al., 2007) to 12 (Goldby et al., 2006; Rasmussen-Barr et al., 2003) weeks. The duration of sessions varied from 45 (Rasmussen-Barr et al., 2003) to 60 (Ferreira et al., 2007; Goldby et al., 2006) min in the studies. The frequency of sessions ranged from one (Rasmussen-Barr et al., 2003) to two (Ferreira et al., 2007) times per week. Table 2 summarizes the other characteristics of included studies.

3.3. Function: Two trials assessed function using the Patient-Specific Functional Scale (Macedo et al., 2012; Verhagen et al., 1998). The nonsignificant difference in function of 0.01 (95% CI: 1.18 to 1.21, N ¼ 310) (Fig. 7); was noted for participants in the stabilization exercises group compared with the general exercises group.

3.4. Risk of bias in the included studies: The studies did not have enough detail for assessing the potential risk of bias. Details regarding the generation and concealment of the random allocation sequence were poorly reported. Six studies presented objective evidence of the random allocation characteristics. The studies presented objective evidence of balance in baseline characteristics. Only three studies stated that the measurements were blinded.

4. Discussion: In the present systematic review, a meta-analysis of 8 studies indicated that stabilization exercises were more effective than general exercises in reducing pain. Five studies demonstrated a significant improvement in disability between patients treated with stabilization exercises compared with those treated with general exercises. Moreover, the meta-analysis of three studies demonstrated that stabilization exercises were as efficacious as manual therapy in decreasing pain and disability. In our meta-analysis the mean of pain in the analyzed studies was 6.01 at baseline, being 2.1 at the end of the stabilization exercises on a 0e10 pain scale. Specifically, the WMD in pain was 1.03 favoring stabilization exercises, what represents an improvement of 39% in pain. Considering pain, for patients with subacute or chronic LBP, the minimally clinically important change for pain on a visual analog scale (0e10) should at least be 20%. If a numerical rating scale (0e10) is used it seems reasonable to suggest that the minimally clinically important change should at least be 25% for patients with chronic LBP (Ostelo and de Vet, 2005). The results of this review are consistent with the findings of a previous systematic review (Ferreira et al., 2006; Macedo et al., 2010) on the effects of stabilization exercise on nonspecific LBP. Our meta-analysis indicated that stabilization exercise can be more effective than general exercise in improving pain and disability in the short term, but it was not superior to manual therapy. In another systematic review by Pereira et al. (Pereira et al., 2012), stabilization exercise and Pilates offered no significant improvement in functionality. Previously, two other meta-analyses (Rackwitz et al., 2006; Wang et al., 2012) reported that specific stabilization exercises was better than ordinary medical care provided by a general practitioner to reduce pain over the short and intermediate terms. However, in a recent meta-analysis, Macedo et al. (Macedo, Maher, Latimer, & McAuley, 2009) demonstrated that stabilization exercises were superior to minimal intervention, but not more effective than manual therapy. Macedo and coworkers’ results are in agreement with those of our meta-analysis (Macedo et al., 2009). Contrary to our results, the meta-analysis by Macedo et al. (Macedo et al., 2009) also demonstrated that stabilization exercises were not more effective than other forms of exercise.



This disagreement can be explained by several different approaches currently in use for stabilization exercise to treat LBP. A standard protocol and definition for stabilization exercises is yet to be established. Therefore, there is a wide variation among studies in how the exercises were named and implemented (Lewis et al., 2005). Nevertheless, multiple studies have shown that not all subjects with LBP benefit equally from stabilization exercise (Hicks, Fritz, Delitto, & McGill, 2005). A recent review of studies has shown that therapy that is specifically directed at well-defined subgroups leads to improved effectiveness of interventions (Karayannis, Jull, & Hodges, 2012). The identification of predictive factors in patients with LBP should allow the prescription of the most appropriate treatment intervention, maximizing the likelihood of a favorable clinical outcome (Brennan et al., 2006; Fersum et al., 2010). In the present review, the included studies did not report concealment allocation or randomization in an appropriate manner. Thus, the effectiveness of stabilization exercises may be even lower in studies with proper randomization and concealment allocation. Our meta-analysis showed that stabilization exercise was as efficient as manual therapy for improving in pain and disability. However, the total number of patients involved in the meta-analysis was too small to identify relatively small disparities between the effects of stabilization exercise and manual therapy. It is difficult to make a definitive and pragmatic recommendation regarding stabilization exercise for patients with LBP. There was a variation in the duration of exercise programs, progression criteria, muscle activation, and type of feedback used during the interventions. However, with the exception of the study of Ferreira et al. (Ferreira et al., 2007) did not inform which protocol was used for stabilization, the protocol used in the studies were based on the protocol proposed by Richardson & Hodges (Hodges and Richardson, 1996; Richardson et al., 1999). Caution is warranted when interpreting the present results given the significant heterogeneity found in primary analyses. The use of different instruments for assessment and intervention programs (session time and duration of intervention) can compromise the comparisons. The studies used different scales and time periods to measure pain intensity (e.g., pain in last 24 h, pain in the last months) and disability (e.g. the Roland Morris Disability Index and the Oswestry Disability Index) and the duration of intervention and the time points of follow-up were different. Despite the differences in frequency and duration, stabilization exercise using the principles proposed by Richardson & Hodges (Hodges and Richardson, 1996; Richardson et al., 1999). were superior to general exercise that prioritizes exercise of superficial muscles. One of the limitations of this review was that the findings were based on relatively low quality data that led to a high risk of bias. Additional research is required to ascertain the positive effects of stabilization exercise over time and to determine their essential attributes, such as mode, intensity, frequency, duration, and timing. New RCTs testing different stabilization exercise for LBP should be conducted to determine the optimal treatment approach. Additionally, it will be important to match exercise prescription to clinical/treatment characteristics of a patient subgroup or individual patient.

5. Conclusion: Stabilization exercises and/or manual therapy can be encouraged as part of musculoskeletal rehabilitation for patients with LBP. However, the best prescription program, needs to be determined by new RCTs.

Performance on the Single-Leg Squat Task Indicates Hip Abductor Muscle Function

Kay M. Crossley, PhD, Wan-Jing Zhang,§ MBBS, Anthony G. Schache, PhD, Adam Bryant,§ PhD, and Sallie M. Cowan,y PhD Investigation performed at Biomechanics Laboratory, Department of Physiotherapy, The University of Melbourne, Melbourne, Australia

Anterior knee pain (AKP) is the most frequent cause of chronic knee pain in adults and results in poorly localized pain around the patellofemoral joint, usually of insidious onset. The high incidence of AKP among active populations is well documented, with incidence rates varying from 9% to 15%. The condition is characterized by a gradual onset of peripatellar pain and is frequently aggravated by common activities of daily living (eg, stair climbing, squatting, ambulation, and kneeling). Therefore, AKP affects many aspects of daily life, including the ability to perform exercise or work-related activities without pain. Accordingly, treatments with the capacity to reduce the burden of AKP are clearly required. A growing body of contemporary evidence indicates that hip muscle function is compromised in people with AKP. This is highlighted by a recent systematic review that found strong evidence for deficits in hip muscle strength (abduction, external rotation, extension) in women with AKP compared with uninjured controls. Similar patterns have also been observed in men. An alternative measure of hip muscle function is hip muscle electromyography (EMG) activation patterns. Two studies observed delayed onset of gluteus medius EMG activity in people with AKP compared with healthy controls. Hence, the available evidence, combined with current clinical consensus, indicates that treatments aimed at improving hip muscle function may result in greater symptom relief (reductions in pain, improvements in physical function) if they are targeted toward those who would most benefit. Consequently, there is a need to be able to clinically identify subgroups of people with chronic AKP who display compromised hip muscle function. A clinical assessment tool often used in screening or patient assessment to determine whether hip muscle function is compromised is the single-leg squat task. Currently, no study has evaluated whether clinical assessment of performance on the single-leg squat task reflects hip muscle function. The relationship between hip muscle strength and control of hip and knee motions during a single-leg squat task remains unclear. Discrepancies between study results may relate to the measurement of hip muscle strength (including how data are scaled or normalized to body size) and methodology for measuring hip and knee joint motions. Furthermore, in prior studies, hip and knee joint motions were recorded using sophisticated equipment only available in gait laboratories. Consequently, there is a need to develop a more simple and clinically applicable procedure to evaluate performance on the single-leg squat task. Visual analysis of movement patterns during a variety of single-leg tasks, designed to assess lower limb neuromuscular control, is currently employed in clinical practice. Studies of clinician agreement on rating performance of single-leg tasks reveal inconsistent results.5,12,20 Accordingly, the authors identified a need for future research in this area. We sought to determine whether the single-leg squat task could be used as a valid and reliable clinical assessment tool capable of identifying subgroups of people with compromised
hip muscle function. Therefore, the aims of this study were to devise a clinical rating of performance on the single-leg squat task based on the consensus of a panel of experienced physical therapists, examine the intra- and interrater reliability for physical therapists when performing a clinical rating of the single-leg squat, and determine whether people who received a ‘‘poor’’ rating on the single-leg squat exhibited different hip muscle function (onset of gluteus medius activity and hip/trunk muscle strength) compared to those who received a ‘‘good’’ rating on the single-leg squat.



We recruited 34 healthy adults, in the age range likely to develop AKP (mean 6 SD: age, 24 6 5 y; height, 1.69 6 0.10 m; weight, 65.0 6 10.7 kg). The mean 6 SD number of exercise sessions per week (duration 30 minutes) was 4.4 6 4.8. Participants were excluded if they had any history of lower limb injury or other disorder that might affect their hip muscle function or capacity to perform the single-leg squat task. The study was approved by the University of Melbourne Human Research Ethics Committee. All participants provided written informed consent. Fifteen of these participants (mean 6 SD: age, 25 6 5 y; height, 1.73 6 0.09 m; weight, 66.8 6 9.8 kg; exercise sessions/wk, 3.3 6 2.9) were included in the reliability study.

Single-Leg Squat Task

All participants were provided with standard instructions on how to complete the single-leg squat task. Participants wore shorts, singlet, and running sandals (provided) and were asked to stand on their dominant leg on a 20-cm box. Leg dominance was determined as the leg with which the participant would kick a ball. Participants were instructed to fold their arms across their chest and to squat down as far as possible 5 times consecutively, in a slow, controlled manner, maintaining their balance, at a rate of approximately 1 squat per 2 seconds. A single investigator demonstrated the single-leg squat procedure. All participants were allowed up to 3 practice attempts. During the single-leg squat trials, the participant was captured on digital video, with the video camera placed approximately 3 m in front of the participant on a tripod at the height of the patient’s pelvis. Digital images were stored in a coded (de-identified) manner and transferred to DVD for assessment.

Electromyographic Procedure

Anterior gluteus medius (AGM) and posterior gluteus medius (PGM) EMG activity was recorded in a manner previously described. Briefly, pairs of silver-silver chloride surface electrodes (Graphics Control Corporation, c/o Medical Equipment Services Pty Ltd, Richmond, Australia) were placed over the AGM muscle belly, 22-mm interelectrode distance, after skin preparation to reduce electrical impedance below 5 KO. For the PGM, bipolar intramuscular electrodes were fabricated from Teflon-coated stainless steel wire 75 mm in diameter (AM Systems, Carlsborg, Washington), with 1 mm of insulation removed and a hook formed by bending the tips of the wire back approximately 1 to 2 mm. The electrodes were sterilized, after insertion into a hypodermic needle (0.7 3 38 mm), before insertion into the PGM under the guidance of real-time ultrasound imaging (7.5-MHz curved linear array transducer; Dornier Performa, Acoustic Imaging Technologies Corp, Phoenix, Arizona). 15 The ground electrode was placed over the iliac crest of the non–test leg. Electromyographic data were sampled at 2000 Hz and bandpass filtered at 20 to 1000 Hz using a Power1401 data acquisition system and Spike5 software (Cambridge Electronic Design, United Kingdom, Cambridge) and analyzed using IGOR Pro (Igor Pro 5, Wavemetrics, Inc, Lake Oswego, Oregon). Participants completed a visual choice reaction time stair-stepping task, where they faced a force plate (model 9286AA [4003600 mm], Kistler, Winterhur, Switzerland; software Bioware version 3.21) placed on a step (combined height 22 cm). This task has been used previously by our research group and is capable of identifying neuromotor control differences between people with and without AKP. Participants stepped up as quickly as possible in response to a light, indicating left or right leg. Data were collected for 5 stepping repetitions. Electromyographic data were expressed relative to foot contact, determined from the vertical component of the ground-reaction force.

Hip External Rotation, Abduction, and Trunk Side Flexion Strength

A handheld dynamometer (Nicholas Manual Muscle Tester; Lafayette Instrument, Lafayette, Indiana) was used to measure isometric hip strength using published methods. For hip external rotation strength, the participants sat with their arms folded and thighs strapped together to maintain neutral hip adduction. The dynamometer was placed over the tibia, 10 cm above the medial malleolus. After 2 warm-up trials, 3 maximum trials were performed, and the peak force was recorded. The distance from the knee joint line to the position of the dynamometer was recorded (m) and used to convert the force (N) data to a torque (Nm). For hip abduction strength, participants lay supine with arms folded across their chest. Straps were used to stabilize the opposite thigh. The dynamometer was placed 10 cm above the lateral knee joint line. After 2 warm-up trials, the peak force from 3 maximal trials was recorded. The distance from the greater trochanter to the position of the dynamometer was recorded (m) and used to convert the force (N) data to a torque (Nm). The trunk side bridge test was used to provide an indication of lateral trunk muscle capacity. In this test, participants lay on one side, supported on their elbow with their opposite hand crossed over the chest. While maintaining a neutral trunk alignment (shoulders, hips, and ankles aligned), the dynamometer was placed just proximal to the greater trochanter. Participants were instructed to push up maximally, lifting their pelvis and trunk. After 2 warm-up trials, the maximum of 3 trials was recorded. Because of the difficulties in determining the moment arm to generate a torque for this measure, force (N) was used. This test was performed on each side.

Determining Criteria for Clinical Rating of Performance on the Single-Leg Squat Task 

A panel of 5 experienced physical therapists (4 with musculoskeletal expertise and 1 with neurological expertise) formed the consensus panel. These physical therapists had different training and clinical experiences. The panel met to discuss the task and to determine the criteria that would be used for future rating.

Clinical Rating of Single-Leg Squat Performance

All ratings were performed with no knowledge of the participants’ results on the hip muscle function tasks. Each member of the consensus panel reviewed a DVD with all digital recordings from all participants. The single-leg squat performance for each participant was assessed by each panel member independently. The panel thenmet as a group to review their decisions. When there was a discrepancy in the rating, the group reviewed the images and then reached consensus on whether the participant could be graded as ‘‘good,’’ ‘‘fair,’’ or ‘‘poor.’’ Of the participants recruited for this study, 9 were rated by the consensus panel as having good performance on the single-leg squat, 12 were rated as having poor performance, and 13 were rated as fair.

Reliability of Clinical Rating of Single-Leg Squat Performance 

Three different physical therapists, 2 with postgraduate musculoskeletal qualifications (average of 10 years of physical therapy practice) from different universities and 1 graduate from a third university, participated in the reliability study. These physical therapists had no formal interaction with the members of the consensus panel in the preceding 5 years. Each physical therapist was provided with a DVD containing digital images from 15 participants: 5 who had been rated good, 5 who had been rated fair, and 5 who had been rated poor. There were no differences in participant characteristics between the 3 groups (P . .05). The 15 participants were selected from those participants whose performance on the single-leg squat task was rated the same by all consensus panel members (ie, there was no discrepancy in the initial ratings). The physical therapists participating in the reliability study were also provided with the clinical rating criteria and one example of a typical participant from each of the 3 rating categories. The participants in the DVD were de-identified. After conducting their rating, the physical therapists returned their scoring sheet and the DVD to 1 examiner. One week later, they were provided with a second DVD. In this DVD, digital images of the same participants were included but in a different order and with different codes. The scoring sheets and DVDs were returned when scoring was completed.

Comparison of Hip Muscle Function Between Participants With Good and Poor Performance on the Single-Leg Squat Task

Those participants rated as fair were excluded from this comparison. Hip muscle function— onset of AGM and PGM EMG activity and hip abduction, external rotation, and trunk side flexion strength—was compared between the participants who were rated as good and poor. There were no between-group mean differences for age, height, or weight (Table 1). The ‘‘good’’ group contained 5 women and 4 men, whereas the ‘‘poor’’ group contained 8 women and 4 men (x2 = 0.269, P = .604).


Data Analysis

The examiner responsible for data extraction and processing was blind to single-leg squat performance ratings. The onset of EMG activity was identified visually from the raw data as the point at which EMG activity increased above the baseline activity.7,8 Traces were displayed in a de-identified manner, with no reference to group, muscle, or trial number. Onset times for each muscle were assessed by 2 separate examiners using data from 15 trials in 2 participants. There were no significant differences between the 2 examiners (P = .62), and the 2 scores were closely matched, with a mean absolute difference of 1.2 milliseconds and a standard deviation of 2.4 milliseconds. Muscle strength data were normalized to the participant’s body weight to enable comparisons between participants.

Statistical Analysis

To determine the reliability of the clinical rating, the agreement between the 3 physical therapists and the consensus panel was determined for each physical therapist using a kappa coefficient. The agreement between the repeated clinical ratings for each physical therapist was also determined using a kappa coefficient. A kappa coefficient of 0.60 was considered acceptable, 0.60 to 0.80 substantial, and 0.80 to 1.00 excellent.22 Electromyographic and muscle strength data were analyzed for normality and homogeneity of variance. Independent samples t tests were used to compare muscle onset, force, and hip and trunk muscle strength between the good and poor performance groups. An analysis of covariance was also performed to evaluate whether gender influenced the outcomes of the between-group comparisons. The alpha level was set at 0.05.

Clinical Rating of Performance on the Single-Leg Squat Task

The expert panel of physical therapists reached consensus on the criteria to rate the performance on the single-leg squat task (Table 2). The 5 criteria were overall impression for the 5 trials, posture of the trunk over the pelvis, posture of the pelvis, hip joint posture and movement, and (5) knee joint posture and movement. The ankle joint was not included in the criteria because it was considered to be reflected in the posture and movement of the knee joint. On the basis of these criteria, the panel determined that a person’s performance could be rated as good, fair, or poor (Figure 1; see video supplement, available online at The descriptions of the requirements to be considered ‘‘good’’ for every component of each criterion are listed in Table 2. To be considered good, the participant needed to achieve all of the requirements for 4 of the 5 criteria for all of the 5 trials. The participant’s performance was considered poor if he or she did not meet all of the requirements for at least 1 criterion for all of the trials. Those participants who could not be rated as good or poor were rated as fair. Importantly, the panel believed that the rating system reflected clinical decision making. For example, a participant rated as good would be considered not to require any intervention to address hip or trunk muscle function. Alternatively, a person rated as poor would require an intervention aimed at improving hip or trunk muscle function. A person rated as fair would be considered to not require any treatment to address the hip or trunk muscle function as the first priority, but the therapist may need to address these factors at some point during the rehabilitation process.



Agreement From Physical Therapists on Clinical Rating of the Single-Leg Squat

Concurrency with the consensus panel was excellent for the 2 more experienced raters (agreement 80%-87%; k = 0.700-0.800) and substantial for the least experienced rater (agreement 73%; k = 0.600). Similarly, intrarater agreement was excellent for rater A (agreement 87%; k = 0.800) and rater B (agreement 80%; k = 0.692) and substantial for rater C (agreement 73%; k = 0.613).

Difference in Hip Muscle Function Between Persons With Poor and Good Rating on the Single-Leg Squat

Participants rated as good performers had significantly earlier onset timing of AGM (mean difference, 2152; 95% confidence interval [CI], 2258 to 248 ms) and PGM (mean difference, 2115; 95% CI, 2227 to 23 ms) than those rated as poor performers (Table 3). Between-group comparisons of hip muscle strength were performed on 7 good performers and 12 poor performers (testing could not be completed on 2 of the good performers because of equipment malfunction). Participants rated as good performers exhibited greater hip abduction torque than poor performers (mean difference, 0.47; 95% CI, 0.10-0.83 NmBw21). There was no difference in hip external rotation torque (mean difference, 0.14; 95% CI, –0.20 to 0.48 NmBw21) between the 2 groups. On the trunk side bridge test, participants rated as good performers produced more force than poor performers on the weightbearing side (mean difference, 1.08; 95% CI, 0.25-1.91 NBw21). The inclusion of gender as a covariate to the between-group comparisons affected results only for the onset of PGM EMG (P = .055).



Anterior knee pain is a leading cause of pain and reduced physical function worldwide that is characterized by reduced quality of life and pain-free performance of workor exercise-related activities. Importantly, there is evidence that knee pain in adults is not self-limiting and that it may precede the development of osteoarthritis. Therefore, it is imperative to study means to reduce the burden of AKP. Nonoperative interventions are recommended to reduce pain and physical limitations associated with AKP. However, people with AKP have heterogeneous presentations, and there is limited information available to guide treatments that are targeted to subgroups of people with AKP. Contemporary clinical expertise, combined with emerging research in AKP, indicates that treatment of hip muscle function may result in greater effects (reductions in pain, improvements in physical function) if such treatments are primarily targeted toward the subgroup of people with AKP who have compromised hip muscle function. Thus, it is imperative to develop and evaluate a clinical assessment tool that is capable of identifying people who have altered hip muscle function. This study developed rating criteria for the clinical assessment of the single-leg squat and established its reliability and validity to detect altered hip muscle function (delayed gluteus medius EMG onset and reduced hip muscle strength).

Clinical Rating of the Single-Leg Squat

The consensus panel, consisting of 5 highly experienced physical therapists, formulated rating criteria for the clinical assessment of the single-leg squat. In contrast to other rating scales, the criteria did not award points for specific components but asked the assessor to evaluate the performance of the participant as a whole. The panel concurred that this was a method typically employed by physical therapists when clinically evaluating a patient’s performance. For example, a poor rating needed to reflect the situation whereby an intervention would be considered necessary to address the patient’s hip/trunk muscle function. By adopting this type of clinical reasoning approach, it was thought that physical therapists would have more confidence with their rating of performance. In contrast, physical therapists may be less likely to estimate ranges of motion from visual observation. Therefore, this holistic approach to the rating criteria facilitated a faster, more efficient assessment of performance, which may be readily transferred to the clinical environment.

Clinical Rating of Performance on the Single-Leg Squat Task Has Acceptable Agreement

The excellent to substantial agreement in the rating of the single-leg squat performance observed between the 3 raters and the consensus panel is considered to be ‘‘acceptable’’ reliability.22 This is an important finding because for the clinical assessment tool to be useful, agreement between and within raters is required. Previous studies in this
area have found varying levels of reliability. In the current study, we attempted to maximize our reliability by incorporating a consensus panel to devise rating criteria for the clinical assessment. Although the rating categories (‘‘good’’, ‘‘fair,’’ and ‘‘poor’’) are similar to those used in previous studies,5,12 the current study incorporated a clinical reasoning element to the rating criteria, which may have enhanced the reliability. Furthermore, in the absence of a ‘‘gold-standard’’ measure of single-leg squat performance, the consensus panel established a gold-standard rating of the assessment of single-leg squat performance. This differentiates our study from previous studies, in which the individual raters were compared with other individual raters. We also used a training DVD, with examples of the different rating categories. The lower concurrence noted by the least experienced rater may indicate that further training is required, perhaps incorporating a feedback element, to enhance reliability in less experienced assessors. Although further studies are required to confirm these results, the assessment of the single-leg squat performance appears to be a tool that can be used with confidence by experienced practitioners in a clinical setting.

Performance on the Single-Leg Squat Indicates Hip Muscle Function

The onset of AGM EMG was delayed in people who were rated as having a poor performance compared with those with good performance on the single-leg squat. This is the first study to evaluate whether clinical rating of performance on a functional task can indicate hip muscle function. This is an important finding because hip muscle dysfunction is considered a factor in the development and persistence of AKP. Because of the unique biomechanics of the patellofemoral joint and its intimate relationship with the femur, several hip muscle factors have the potential to influence the magnitude and distribution of patellofemoral joint stress. The prevailing theory is that aberrant hip muscle function manifests as altered hip and/or knee biomechanics during functional tasks (eg, walking, running, stair ambulation, jumping, and landing),23 but currently there is conjecture surrounding the precise nature of this relationship. The many methodological issues that vary between studies (including study populations, measurement methods, and task choice) make direct comparisons difficult. Notwithstanding the need for more research to confirm the relationship between hip muscle function and hip and/or knee biomechanics during functional activities, hip muscle dysfunction may warrant targeted interventions if it can be identified. Increasingly, the timing (or coordination) of muscle activations is considered important in musculoskeletal pain conditions, and delayed onset of gluteus medius activity has been identified in people with AKP. Measurement of EMG requires sophisticated laboratory equipment and considerable expertise. Thus, the ability of a simple clinical test to provide an indication of the gluteus medius EMG timing has useful applications for physical therapists. Hip abduction strength was 29% lower and lateral trunk strength (measured with the side bridge test) was 23% lower in those with poor compared with good performance on the single-leg squat. Therefore, the clinical assessment of performance on a functional task was able to indicate hip and trunk muscle strength. This finding is important because hip muscle strength is a feature of AKP, with potential for change with an intervention. Furthermore, in a study of college athletes, Leetun and colleagues 17 observed that reduced hip muscle strength was a predictor of sustaining a lower limb injury over one athletic season. Further studies are required to confirm the role of hip muscle dysfunction in the development of AKP in diverse populations. Nonetheless, the ability to indicate hip muscle strength from a single clinical test has considerable implications for the assessment of at-risk persons or to guide and monitor treatments. The interrelationships between hip muscle function (strength or neuromotor control), trunk muscle function, performance on a functional task, and the development or persistence of AKP require further elucidation. However, the weight of current evidence suggests that altered hip or trunk muscle function may be an important factor in AKP. Our study results, if confirmed in future studies, indicate that the clinical assessment of the single-leg squat may be capable of identifying patients with hip muscle dysfunction and hence may be a tool that can be used by clinicians when selecting treatment options (eg, strengthening or retraining hip muscle function) targeted to their patients’ findings. In addition, these results may be used in clinical research to establish subgroups of people with hip muscle dysfunction and evaluate targeted treatments.

Limitations and Future Studies

In the current study, assessment of performance on a single-leg squat task used a protocol that reflected routine clinical practice. Greater standardization of the test protocol (eg, squat depth, speed of squat, and the use of markers to identify anatomical landmarks) may enhance the reliability and vaidity of this test. In addition, because foot posture and motions may influence lower limb function via the closed kinetic chain, future studies could also include an evaluation of the foot and ankle. The study used only 5 experienced physical therapists, from different training and experiential backgrounds, in the consensus panel. The results of the consensus panel could be strengthened in future studies by evaluation of the assessment criteria by a broader cohort of physical therapists. Similarly, the reliability study could be repeated, using different physical therapists and different training techniques. Although we used a training DVD, future studies should evaluate the additional benefits of a more intensive training program, perhaps incorporating interactive feedback. Despite the study’s limitations, the results of this study indicate that the clinical assessment of the singleleg squat has clinical utility to determine hip muscle function. Future studies are required to establish the repeatability of a person’s performance on such a task and to determine the effects of targeted interventions on the performance of the single-leg squat. Such studies may identify whether the single-leg squat task is sensitive to change. Furthermore, additional studies are required to identify whether the results observed in the current study differ between men and women. In the current study, healthy participants were chosen because people with AKP frequently report pain with a single-leg squat that may affect the results. Research is now needed to explore whether similar results are also evident in a group of people with AKP.

Clinical Relevance

This study identified that the clinical assessment of performance on the single-leg squat is a reliable tool that may be used to identify people with hip muscle dysfunction.

Rehabilitation of the Knee After Medial Patellofemoral Ligament Reconstruction

Donald C. Fithian, MDa,b,c,*, Christopher M. Powers, PhD, PTd,e, Najeeb Khan, MDb,c

Rehabilitation of the extensor mechanism after patellar stabilization surgery should be based on a sound understanding of lower limb mechanics, anatomy, mechanics of the injured or repaired extensor  echanism, and a careful evaluation of the patient. Abnormal anatomic features and control deficits can, and often do, affect function of the patellofemoral joint. Current evidence suggests that patellofemoral rehabilitation should address dynamic lower extremity function, such as abnormal lower extremity motions stemming from impairments proximally (ie, hip) or distally (ie, foot), because such motions can influence the dynamic quadriceps angle (Q-angle) (Fig. 1).1 In addition, many patients with episodic patellar instability have preexisting anatomic deficiencies that may affect rehabilitation.2 Joint surface injury and degenerative articular lesions also may call for variations to the rehabilitation protocol. The purpose of this article is to provide the reader with an understanding of the current state of lower limb rehabilitation for patients who have undergone medial patellofemoral ligament (MPFL) reconstruction.


Fig. 1. A diagrammatic representation of the various potential contributions of limb malalignment and malrotation to increase Q-angle: (1) hip adduction, (2) femoral internal rotation, (3) genu valgum, (4) tibial external rotation, and (5) foot pronation. (From Powers CM. The influence of altered lower-extremity kinematics on patellofemoral joint dysfunction: a theoretical perspective. J Orthop Sports Phys Ther 2003;33(11):644; with permission.)


MPFL reconstruction is a painful procedure. Severe postoperative pain can interfere with active muscle control. Pain can also impede progress with range of motion (ROM). Operating at or near the medial epicondyle of the knee often is associated with postoperative stiffness because of the higher degrees of motion of the injured soft tissues relative to the femur during knee flexion and extension. It is important to address this tendency aggressively in the early postoperative phase to avoid stiffness. Once the motion has been established, medial pain and knee stiffness caused by scarring at the femoral attachment of the graft are rare problems. Swelling, either as free intra-articular fluid (effusion) or as soft tissue edema, also can interfere with joint motion. In addition, effusion inhibits quadriceps function and may be harmful to intra-articular structures, such as articular cartilage. Both pain and swelling can be addressed in various ways. Strict elevation of the limb and limited activity in the first 1 to 2 days postoperation allow the acute inflammatory phase to pass without further perturbation by overaggressive therapy. During that time, cold therapy may be helpful, whether in the form of ice packs or commercially available cold therapy units. The use of cold therapy to reduce local pain, inflammation, and swelling is a traditional mainstay of treatment after injury.


Prolonged joint immobilization results in the loss of ground substance and dehydration of the extracellular matrix.4,5 These changes reduce the distance between fibers within the matrix, causing friction and adhesion that reduce suppleness in periarticular ligaments and cartilage. In contrast, mobilization of an injured joint is associated with enhanced collagen synthesis and more optimal fiber realignment within the tissues, reversing the processes seen with immobilization. It is not always possible to move joints immediately after surgery, but early motion is clearly desirable.6 Experience has shown that immediate, controlled ROM is not detrimental to fixation or graft development in well-positioned and securely fixed ACL grafts. Furthermore, early motion seems to be beneficial to the limb as a whole by reducing pain, promoting healthy development of cartilage and periarticular tissues, and preventing scar formation and capsular contractions.7 Therefore 1 goal of MPFL reconstruction is to use a competent graft, place it so that it will not be harmed by physiologic motion, and secure it well enough to withstand the loads associated with normal joint motion. After MPFL reconstruction, loss of full passive extension is rarely seen. However, it can be difficult to regain full flexion. In addition, failure to achieve full active extension (residual extensor lag) has been reported at short and long-term follow-up. The reasons for motion difficulties after MPFL reconstruction seem to be related to the dissection and MPFL graft location. Cyclops lesions, such as those that can physically block knee extension after ACL reconstruction, have not been reported after MPFL reconstruction. But capsular and/or infrapatellar fat pad contracture, quadriceps inhibition,  and poorly positioned grafts can lead to the complications noted earlier. An early goal of rehabilitation after MPFL reconstruction is to reestablish full knee extension. Unlike ACL reconstruction, return of passive knee extension does not guarantee full active extension. For that to occur, attention must focus on quadriceps
strengthening (see later discussion for details). Pain and swelling can be mitigated with electrical stimulation, cold therapy, and compression wraps. Passive patellar glides should be instituted as soon as tolerated, to reestablish normal passive patellar mobility within the trochlear groove in all directions (superiorly, inferiorly, medially, and laterally). Many patients have considerable apprehension because of their prior experience with patellar hypermobility, and mobilization can improve confidence in their newly acquired patella stability. Return of passive flexion can be difficult for several reasons. If the graft is not positioned properly it may tighten in flexion and tether the joint. Injury around the medial epicondyle, whether traumatic or surgical, is also associated with persistent joint stiffness if early attention is not given to full knee flexion in the rehabilitation program. The goal is to exceed 90 flexion within 6 weeks postoperatively. If that goal is achieved, then in the authors’ experience limited knee flexion will not be a problem. On the other hand, delay in achieving greater than 90 of knee flexion may allow scar tissue proliferation and formation of adhesions around the graft and within the medial knee soft tissues. Manipulation may be required to regain full knee motion if flexion past 90 is not accomplished by week 6.


Surgery of the extensor mechanism is particularly prone to cause quadriceps inhibition and dysfunction, and every effort should be made to regain quadriceps control, strength, and endurance. If the reconstruction has been performed properly, then controlled quadriceps contractions pose no threat to the graft. Quadriceps setting exercises should be started immediately after the surgery to keep the patellar tendon and infrapatellar fat pad stretched to their full length and to restore neuromuscular control. Resisted quadriceps and hamstring strengthening should be progressively used as the initial pain subsides. A strong body of levels 1 and 2 studies indicates that electrical stimulation is helpful in reducing strength loss after knee ligament surgery. Classic studies on rehabilitation after ACL reconstruction have demonstrated the value of electrical stimulation compared with voluntary contractions alone for reducing postoperative abnormalities of gait and strength. These earlier studies are supported by recent works, indicating that electrical stimulation combined with voluntary exercises is superior to voluntary exercises alone in restoring normal gait and strength. A recent review of these studies recommended neuromuscular electrical stimulation in combination with volitional contraction. Previous investigators have emphasized early application of this approach, when muscle inhibition is most pronounced, to gain maximum effect.7 Despite differences between MPFL and ACL reconstruction surgeries, there are enough similarities in postoperative neuromuscular deficiencies to suggest that strategies that are found to be successful after ACL reconstruction should be considered for those who have undergone MPFL reconstruction.


MPFL reconstruction, whether performed alone or in combination with osteotomy of the tibial tubercle, is not affected by axial loading of the joint. For this reason, there should be no a priori reason to limit weight bearing after surgery as long as axial rotation of the limb is not allowed. The limb should be splinted in a brace during weight-bearing activities for 4 to 6 weeks postoperatively or at least until limb control is sufficient to prevent falls and rotational stress on the knee. Early weight bearing should follow a gradual progression from full protection with a rigid brace locked at full extension to an unlocked brace with crutches. Gradual increase to full weight bearing should be permitted as quadriceps strength is restored. Care should be taken during weight bearing to prevent dynamic knee valgus and hip internal rotation, which can cause abnormal loads on the healing graft. This is important because many patients with patellofemoral disorders have preexisting deficiencies in proximal limb control that can contribute to these motions. When postoperative quadriceps weakness and neuromuscular inhibition is superimposed on poor proximal control, unprotected weight bearing can result in abnormal forces on the healing graft. A frequently cited study of graft healing in dogs suggested that 8 to 12 weeks are required for tendon-to-bone healing within tunnels to support graft tension without the risk of slippage.15 For this reason, care is needed to avoid any rotational activity during the first 3 months postoperatively. Unprotected single-leg stance on the operated knee should be avoided until satisfactory proximal limb control has been achieved. The postoperative brace should be removed for resisted flexion and extension strengthening as well as other controlled rehabilitative exercises that do not cause knee valgus or axial rotational torque that would jeopardize the graft fixation. Treatment to enhance proximal control can be started preoperatively and then immediately after surgery. Postoperatively, patients should perform non–weight bearing exercises targeting the hip abductors, external rotators, and extensors. When performing strengthening exercises for the gluteus medius, the patient must take care to minimize the contribution of the tensor fascia lata, because contraction of this muscle contributes to medial rotation of the lower extremity. Once the patient is able to isolate the proximal muscles of interest in non–weight bearing exercises, progression to weight-bearing activities can begin. Facilitation of normal gait is an essential component of the overall treatment plan. This is particularly important for the returning athlete (especially runners), in whom even a slight gait deviation can be compounded by repetitive loading. The clinician should pay particular attention to the quadriceps avoidance gait pattern (walking with the knee extended or hyperextended). Because knee flexion during weight acceptance is critical for shock absorption,16 this key function must be restored to prevent the deleterious effects of high-impact tibiofemoral joint loading. The primary causes of quadriceps avoidance are pain, effusion, and quadriceps muscle weakness. As these impairments are addressed in other aspects of treatment, the clinician should keep in mind that resolution of symptoms may not readily translate into a normalized gait pattern. This is particularly evident in a patient with long-term pain and dysfunction. Movement patterns can be learned, and the patient may need to be reeducated with respect to key gait deficiencies. Electromyographic (EMG) biofeedback can be an effective tool for this purpose (Fig. 2).


Fig. 2. EMG biofeedback can be used to facilitate quadriceps recruitment during functional tasks. (Reproduced from Powers CM, Souza RB, Fulkerson JP. Patellofemoral joint. In: Magee DJ, Zachazewski JE, Quillen WS, editors. Pathology and intervention in musculoskeletal rehabilitation. St. Louis (MO): Saunders Elsevier; 2008. p. 628; with permission.)


Functional training of the limb can begin in earnest 3 months after surgery. At this time, the patient should be introduced to the concept of neutral lower extremity alignment. This involves alignment of the lower extremity such that the anterior superior iliac spine and knee remain positioned over the second toe, with the hip positioned neutrally (Fig. 3). Postural alignment and symmetric strengthening should be emphasized during all exercises (see Fig. 3). If the patient has a difficult time maintaining proper lower extremity alignment during initial weight-bearing exercises, femoral strapping can be used to provide kinesthetic feedback and to augment muscular control and proprioception (Fig. 4). Also, taping or bracing of the patellofemoral joint may be done if pain is limiting the patient’s ability to engage in a meaningful weight-bearing exercise program. Partial squats, which may have been started already in a controlled environment under supervision, can be advanced to incorporate a BOSU ball (BOSU Fitness LLC, San Diego, CA, USA) or a similar device to facilitate proximal control. Again many patients may exhibit abnormal movements or postures during training tasks. As such close supervision may be necessary to ensure proper execution. Once the patient understands the proper movement and goal of the task, continued performance in front of a mirror provides useful feedback. As strength, control, and balance progress, single-leg activities may be initiated. This is the final step before returning to full unrestricted activity. Considering that most patients are conditioned by their preoperative apprehension caused by patellar instability and that some patients may not have performed single-leg squats on the operated leg for years before the operation, the patient may not progress to this stage before 5 to 6 months after the reconstruction. In any case, rehabilitation from this point onward requires careful assessment and progressive development of proximal lower limb control.


Fig. 3. Weight-bearing activities (such as the single-leg squat shown in the figure) should be done with particular attention to proper alignment of the pelvis, hip, knee, and ankle. (Reproduced from Powers CM, Souza RB, Fulkerson JP. Patellofemoral joint. In: Magee DJ, Zachazewski JE, Quillen WS, editors. Pathology and intervention in musculoskeletal rehabilitation. St. Louis (MO): Saunders Elsevier; 2008. p. 631; with permission.)


Patients should be encouraged to return to their sport or activity gradually once they can achieve satisfactory single limb dynamic control. With competitive or recreational athletes who will be returning to full participation, plyometric training (ie, jump training) should be considered during this phase of the rehabilitation program. As patients, particularly athletes, return to sport activities, repetitive forces applied through the knee joint must be controlled adequately to allow continued healing of the injured or repaired tissues. During an extended time of recovery, such as following knee extensor mechanism surgery, quadriceps and hip muscle strength should be maintained (ie, maintenance program) through careful application of resistive exercises. Experience has shown that patients can expect to return to unrestricted activities by 6 months to 1 year postoperatively.


Artigo original:

Musculatura Abdominal

A musculatura abdominal profunda é essencial para termos uma boa estabilidade lombopelvica. Quando não acionamos da forma correta o transverso abdominal, temos uma reação em cadeia:

  • Instabilidade de tronco
  • Flexão de quadril instável
  • Psoas traciona anteriormente as vértebras lombares
  • Anteversão pélvica e hiper lordose lombar

Essa instabilidade nos leva à ações musculares ineficientes e aumenta a predisposição ao desenvolvimentos de algumas patologias como: hérnia discal e lombalgia.


The initial effects of a Mulligan’s mobilization with movement technique on dorsiflexion and pain in subacute ankle sprains

Natalie Collins, Pamela Teys, Bill Vicenzino*
Department of Physiotherapy, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
Received 17 December 2002; received in revised form 25 July 2003; accepted 21 August 2003


The lateral ligament complex of the ankle, described as the body’s ‘‘most frequently injured single structure’’ (Garrick, 1977), is mechanically vulnerable to sprain injury. At extremes of plantarflexion and inversion, influenced by the shorter medial aspect of the ankle mortise, the relatively weak anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) are prone to varying grades of rupture, often via minimal force (Hockenbury and Sammarco, 2001). Immediate inflammatory processes produce acute anterolateral pain and oedema, with avoidance of movement and weight bearing (Wolfe et al., 2001). Subsequent losses of joint range, particularly dorsiflexion, and muscle strength results in significant gait dysfunction. Recent data from our laboratory highlights the presence of a dorsiflexion deficit not only in the acute stage, but also in the subacute stage (Yang and Vicenzino, 2002). Early physiotherapy intervention consists of rest, ice, compression, elevation (RICE) and electrotherapy modalities to control inflammation, as well as manipulative therapy and therapeutic exercise techniques to address impairments of movement and strength (Wolfe et al., 2001; Hockenbury and Sammarco, 2001). Green et al. (2001) investigated the impact of combining nonweight-bearing talocrural anteroposterior (AP) passive mobilisations, believed to restore dorsiflexion range, with the RICE protocol in the treatment of acute ankle sprains. The experimental group ðn ¼ 19Þ demonstrated a more rapid improvement in pain-free dorsiflexion and function than the control group ðn ¼ 19Þ who were treated solely with RICE. This provides important evidence substantiating the role of passive joint mobilizations in an acutely injured population. The mobilization with movement (MWM) treatment approach for improving dorsiflexion post-ankle sprain combines a relative posteroanterior glide of the tibia on talus (or a relative anteroposterior glide of the talus on the tibia) with active dorsiflexion movements, preferentially in weight bearing (Mulligan, 1999). Claims of rapid restoration of pain-free movement are associated with MWM techniques generally (Mulligan, 1993, 1999; Exelby, 1996). Through examination of the effects of MWM on ankle dorsiflexion in asymptomatic mildly restricted ankle joints, Vicenzino et al. (2001) found that both the weight bearing and non-weightbearing variations of the dorsiflexion MWM technique produced significant gains in dorsiflexion range. However, weight-bearing treatment techniques are widely believed to be superior to non-weight-bearing techniques, as they replicate aspects of functional activities (Mulligan, 1999). Acute ankle sprains, whilst having marked reduction in dorsiflexion range of motion, are frequently painful in full weight bearing, and weightbearing techniques are not clinically indicated. The subacute ankle sprain is characterized by significant residual deficits in dorsiflexion (Yang and Vicenzino, 2002) and the capacity to fully weight bear, making it a good model on which to study the initial effects of weight-bearing MWM on dorsiflexion. The mechanism of action of manipulative therapy has been the focus of several reports in recent times, however spinal manipulative therapy appears to be the common subject of research. A synopsis of current evidence for the initial mechanism of action of manipulative therapy indicates in part a neurophysiological basis (Vicenzino et al., 1996, 1998, 2000). Manipulative therapy treatment techniques studied have exhibited non-opioid hypoalgesia to mechanical but not thermal pain stimuli (Vicenzino et al., 1995, 1998). The primary objective of this study was to test the hypothesis that application of Mulligan’s MWM technique for talocrural dorsiflexion to subacute lateral ankle sprains produces an initial dorsiflexion gain, and simultaneously produces a mechanical but not thermal hypoalgesia.


The double-blind randomized controlled trial incorporated repeated measures into a cross over design, in which each participant served as their own control.

Participants: Sixteen participants, eight males and eight females aged 18–50 (average 28.25 years and standard deviation 9.33 years), were recruited through the University Physiotherapy Clinic, local physiotherapy practices and sporting clubs, and University advertising. The primary criterion for inclusion was a grade II ankle lateral ligament sprain that was sustained on average 40 days (724 days standard deviation) prior to testing. We defined this sprain as ‘‘an incomplete tear of the ligament with mild laxity and instability (and) slight reduction in functiony’’ (Safran et al., 1999); A minimum pain-free dorsiflexion asymmetry of 10mm on weight-bearing measure (Vicenzino et al., 2001), anterolateral ankle tenderness, and full pain free weightbearing capacity were also required. Acute ankle sprains were excluded due to the potential for exacerbation of pain with repeated testing on the outcome measures. Exclusion also occurred if fracture or intra-articular ankle effusion were clinically detectable, or if there was a recent history of other lower limb or lumbar spine conditions. Physiotherapists and physiotherapy students were excluded to remove a potential source of bias from the participants. Ethical clearance was obtained from the relevant Institution Review Board for ethics at the University of Queensland, and all participants provided informed consent.

Outcome measures
Dorsiflexion: Weight-bearing dorsiflexion (DF), found to have excellent inter- and intra-rater reliability (Bennel et al., 1998), was measured using the knee-to-wall principle. The participant stood in front of a wall, with the test foot’s second toe and midline of the heel and knee maintained in a plane perpendicular to the wall. The participant slowly lunged forward into talocrural dorsiflexion until the knee contacted the wall, and progressively moved the foot back to the point where the knee could just touch the wall with the heel sustained on the ground. This represented end of range dorsiflexion, and the distance between the wall and second toe was measured in millimetres using a tape measure. The examiner ensured maintenance of heel contact via verbal instructions and manual contact with the calcaneum. Vicenzino et al. (2001) found this measure to be more sensitive in detecting treatment effects than an angular weight-bearing measure and a non-weight-bearing measure.

Pain: Quantitative measures of pain were obtained via pressure and thermal pain threshold. Pressure algometry, which has demonstrated reliability (Pontinen, 1988), was used to measure pressure pain threshold (PPT) at three lower limb sites:over the proximal third of the tibialis anterior muscle belly; (2) directly distal to the lateral malleolus over the CFL; directly anterior to the lateral malleolus over the ATFL. A digital pressure algometer (Somedic AB, Farsta, Sweden) was used to measure the pressure applied to the test site by a rubbertipped probe (area 1 cm2), which was positioned perpendicular to the skin. The pressure was applied at a rate of 40 kPa/s. Activation of a button by the participant at the precise moment that the pressure sensation changed to one of pain and pressure, signalled cessation of pressure application, and froze the measurement onscreen for manual recording. The Thermotest System (Somedic AB, Farsta, Sweden) measured hot and cold thermal pain threshold (TPT). A rectangular contact thermode was manually positioned over two sites: (i) the proximal third of the tibialis anterior muscle belly, and (ii) over the ATFL, extending from the anteroinferior border of the lateral malleolus toward the toes at an angle that allowed maximal contact with the foot contours. The hot or cold stimuli were increased at a rate of 1ºC/s from a baseline of 30ºC. Participants pressed a button at the precise moment that the thermal sensation changed to one of pain and heat for heat pain threshold, and one of pain and cold for cold pain threshold. At this point, stimulation ceased and the temperature reached was manually recorded. Automatic cut-off points of 52ºC and 2.5ºC were adopted to ensure safe stimulus application.

Treatment conditions: Three treatment conditions, consisting of MWM for dorsiflexion, placebo and a no-treatment control, were studied. During the treatment condition, the dorsiflexion MWM technique was performed on the symptomatic talocrural joint, as described by Mulligan (1999). With the participant in relaxed stance on a bench, a nonelastic seatbelt was placed around the distal tibia and fibula and the therapist’s pelvis, with foam cushioning the Achilles tendon. A backward translation by the therapist imparted tension on the seatbelt and a posteroanterior tibial glide, while the talus and forefoot were fixated with the webspace of one hand close to the anterior joint line. The other hand was positioned anteriorly over the proximal tibia and fibula to direct the knee over the second and third toes to maintain a consistent alignment of the distal leg and foot. The glide was sustained during slow active dorsiflexion to end of pain-free range, with the seatbelt kept perpendicular to the long axis of the tibia throughout movement, and released after return to the starting position. Three sets of 10 repetitions were applied, with one minute between sets (Exelby, 1996). Pain experienced during treatment resulted in immediate cessation of the technique and exclusion from the study. The placebo condition replicated the treatment condition, with the following exceptions. The seatbelt was placed over the calcaneum, and only minimal tension imparted to take up the slack. One hand remained on the proximal tibia and fibula, however the other hand was positioned across the metatarsal bases. Instructions were given to produce a small inner range dorsiflexion while the seatbelt was maintained perpendicular to the tibia. An identical number of repetitions, sets and interval period were used. In the control condition, the participant assumed the same relaxed stance position as for treatment and placebo, and maintained this for five minutes. No manual contact occurred between the therapist and participant.

Procedure: A preliminary session, during which a clinical examination and the three outcome measures were performed on both ankles, was conducted initially to determine the participant’s suitability for inclusion. This session also served to familiarize participants with testing procedures. Suitable participants returned for three testing sessions within one week of the initial appointment. These were scheduled at similar times of the day to prevent diurnal variations in joint range and pain, and allow a 24-h interval for wash-out of any treatment effects. Testing was conducted in an environment-controlled laboratory, with constant temperature and humidity. Each testing session began with the asymptomatic then symptomatic ankles undergoing each of the three outcome measures. With the participant in side lying, a splint was applied to the testing ankle to maintain a standardized 10 of plantarflexion. PPT and TPT measures were then conducted in an order randomized by the toss of a coin, followed by weight-bearing dorsiflexion. Three repetitions of each measure were taken. The examiner then left the laboratory while the therapist then entered and applied one of the treatment conditions (MWM, placebo, control) to the symptomatic ankle. Following treatment, outcome measures were repeated on the symptomatic ankle by the examiner to evaluate the effect of treatment. This  procedure facilitated blinding of the examiner. The participant was unaware of the aim of the study and which treatment condition was under investigation. Over the 3 days of involvement in the primary study, each participant experienced all three treatment conditions in a randomised order as determined by the roll of a dice by the therapist.



Acceptable intrarater reliability was determined through analysis of pre-treatment data from the three testing sessions. The intraclass correlation coefficient (ICC) and standard error of measurement (SEM) data for the pain measures are presented in Table 1. The ICC and SEM for the dorsiflexion measure were 0.99 and 3.50 mm, respectively. The ICC for the pain measures ranged from 0.95 to 0.99. The SEM for pressure pain threshold ranged from 5.57 to 12.00 kPa, and the thermal pain threshold SEM ranged from 0.22 to 0.74C. Note that both the size of the error (SEM) and the ICC are indicative of reliable measures.

Data management and analysis

Two independent variables were incorporated into the research design; TREATMENT (MWM, placebo, control), and TIME of application (pre- and post-intervention). Three dependent variables, measures of pressure pain threshold (PPT), thermal pain threshold (TPT) and dorsiflexion (DF), were evaluated. Prior to analysis, triplicate DF, PPT and TPT data were averaged. Data pertaining to two of the participants were excluded from analysis; subject 4 who had a post-testing MRI that revealed an osteochondral lesion of the talus and ankle joint effusion, and subject 7 who experienced pain during the MWM technique. Pre-experiment differences between sides (symptomatic–
asymptomatic) were evaluated by paired t-tests ða ¼ 0:05Þ: A two-factor analysis of variance (ANOVA) was then performed on each of the three dependent variables to test the hypothesis that MWM produced changes in excess of placebo and control from pre- to postapplication. Any significant interaction effects were followed up with tests of simple effects. Post hoc tests of main effects were performed in the absence of an interaction. A Bonferroni adjustment ðaadjusted ¼ 0:05=3 ¼ 0:017Þ was used to interpret results of the pair wise tests of simple effects and to adjust for any type I error resulting from multiple comparisons.


Pre-experiment deficits in outcome measures: Pre-experiment values for dorsiflexion and pain measures of the affected and unaffected ankles are displayed in Table 2. Statistical analysis of side-to-side differences revealed a deficit only for dorsiflexion (DF) (t ¼ 5:689; Po0:001) and pressure pain threshold over the anterior talofibular ligament (PPT ATFL) (t ¼ 2:570; P ¼ 0:025). No such deficits in thermal pain threshold (TPT) were found.

Primary study
Dorsiflexion: A significant interaction time by condition effect for the dorsiflexion outcome measure was detected by the ANOVA (Fð2;26Þ ¼ 7:817; P ¼ 0:002). The interaction plot is shown in Fig. 2. Post hoc analysis revealed a significant treatment effect for dorsiflexion from pre- to post-application (t ¼ 2:870; P ¼ 0:013). The post hoc analysis for the pre- and post-application data showed no significant differences between the placebo (t ¼ 1:343; P ¼ 0:202) and control (t ¼ 1:324; P ¼ 0:208) conditions. Table 3 presents the dorsiflexion data.

figure2 table2 table3 table4

Pain: The data for pain thresholds for pressure, cold and heat stimuli are expressed as mean and standard deviation in Table 4. Statistical analysis of the pain related data revealed no interaction effects (see Fig. 2 for plots). However, there were main effects for time for PPT ATFL (Fð1;13Þ ¼ 6:401; P ¼ 0:025) and PPT TA (Fð1;13Þ ¼ 9:17; P ¼ 0:010). Post hoc tests of simple effects demonstrated significant pre- to post-differences for PPT ATFL in the placebo condition (t ¼ 2:774; P ¼ 0:016) (Fig. 3), but no significant change in PPT TA. No significant time or condition effects were evident for PPT CFL, or the TPT measures.


Application of the dorsiflexion mobilization with movement (MWM) technique to patients with subacute lateral ankle sprains produced a significant immediate improvement in dorsiflexion, but had no significant initial effect on mechanical and thermal pain threshold measures. This dorsiflexion gain following manipulative therapy parallels findings by Green et al. (2001) in acute ankle injuries, and Vicenzino and colleagues’ (2001) study of asymptomatic minimally restricted ankles. Current and previous research findings suggest that the predominant mechanism of action for the dorsiflexion MWM technique is most likely mechanical, rather than a direct hypoalgesic effect. An excessive anterior displacement of the talus is believed to occur during plantarflexion/inversion injury and persist with residual laxity of the anterior talofibular ligament (ATFL) (Mulligan, 1999). Denegar et al. (2002) reported increased ATFL laxity and restricted posterior talar glide in twelve athletes who had sustained an ankle sprain 6 months earlier and had since returned to sport. The clinical rationale given for the anteroposterior glide component of the weight-bearing dorsiflexion MWM technique is to reduce any residual anterior displacement of the talus (Mulligan, 1999). Mulligan (1993, 1999) proposed that correction of the restricted posterior glide, via repetitions of DF with a sustained anteroposterior talar mobilization (mechanically similar to posteroanterior tibial glide on talus), restores the normal joint kinematics even after release of the glide. The mechanism by which this occurs in the presence of ATFL laxity requires further examination. Despite the presence of a reduction in pressure pain threshold (PPT) over the ATFL, the MWM technique did not produce a significant change in local PPT in the initial post-treatment period. The dorsiflexion MWM’s mechanism of action therefore appears to be mechanical, and not directly via changes in the pain system. The conduct of further research is required to identify a precise mechanism. While small but non-significant increases in pressure pain threshold occurred following treatment and control application, it was the placebo condition that produced a statistically significant improvement in pressure pain threshold over the ATFL. It is possible that the gentle inner range dorsiflexion movement performed during the placebo condition was more successful at altering the local pathophysiology peripherally at the ankle or via central neurophysiological mechanisms than the sustained end of range glide and larger range movement of the MWM technique. The application of small amplitude accessory glides of joints in an acute and painful state has been previously advocated (Maitland, 1985) and their benefits in the subacute population requires further investigation. The reasonably small sample size should also be considered to have influenced the results of the statistical analysis. It is possible that the pain measures have a lower sensitivity to change than the dorsiflexion measure, yet the significant dorsiflexion improvement seen post-treatment indicates that range gains are the predominant effect. In addition the failure to elicit prestudy deficits in thermal pain thresholds most likely lessened the likelihood of detecting a change with treatment. Research using a larger sample size and possibly acute ankle sprains with deficits in thermal
pain, should they exist, may reveal differences not detected in this study.


Mulligan’s dorsiflexion mobilization with movement technique significantly increases talocrural dorsiflexion initially after application in subacute ankle sprains. The absence of hypoalgesia post-application suggests a predominant mechanical rather than hypoalgesic effect behind the technique’s success. Further research using a larger sample is required to determine the exact mechanism behind this.

Hydrotherapy on exercise capacity, muscle strength and quality of life in patients with heart failure: A meta-analysis

Mansueto Gomes Neto, Cristiano Sena Conceição, Fabio Luciano Arcanjo de Jesus , Vitor Oliveira Carvalho

Heart failure (HF) is clinically characterized by exercise intolerance, poor health related quality of life (HRQOL) and high mortality. Exercise training is a well-established method to improve exercise intolerance and to restore HRQOL in patients with HF. However, the most efficient modality is unknown. In this context, hydrotherapy (i.e. exercise in warm water) has been proposed as an alternative tool in the rehabilitation of patients with HF. There is no meta-analysis of the efficacy of this intervention in HF patients. The aim of this systematic review with meta-analysis was to analyze the published randomized controlled trials (RCTs) that investigated the effects of hydrotherapy on exercise capacity and HRQOL in HF patients. This review was planned and conducted in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. We searched for references on MEDLINE, EMBASE, CINAHL, PEDro, and the Cochrane Library up to May 2014 without language restrictions. This systematic review included all RCTs that studied the effects of hydrotherapy in aerobic capacity, muscle strength and/or HRQOL of the HF patients. Two authors independently evaluated and extracted data from the published reports. Methodological quality was also independently assessed by two researchers. Studies were scored on the PEDro scale a useful tool for assessing the quality of physical therapy trials based on a Delphi list that consisted of 11 items with a score range of 0 to 10.



Pooled-effect estimates were obtained by comparing the least square mean percentage change from baseline to study end for each group. Two comparisons were made: hydrotherapy versus control group (non exercise) and hydrotherapy versus aerobic exercise group. All analyses were conducted using Review Manager Version 5.0 (Cochrane Collaboration). Six papers met the eligibility criteria. Fig. 1 shows the PRISMA flow diagram of studies in this review. The results of the assessment of the PEDro scale are presented individually in Table 1. The final sample size for the selected studies ranged from 14 to 25 and mean age of participants ranged from 51 to 75 years. All studies analyzed in this review included outpatients with documented HF and New York Heart Association (NYHA) classes II–III. Table 2 summarizes the characteristics. Hydrotherapy was considered as aerobic and strength exercises in warm water and the duration of the programs ranged from 3 to 24 weeks. Regarding the time of the session, there was a variation from 30  to 90 minutes. The frequency of sessions was three times per week in three studies and five times per week in others. Four studies assessed peak VO2 as an outcome, two compared hydrotherapy versus no exercise [10,11] and two hydrotherapy versus conventional aerobic exercise in land. The meta-analyses showed a significant improvement in peak VO2 of 2.97 mL·kg−1 ·min−1 (95% CI: 1.99, 3.94, N = 42) for participants in the hydrotherapy group compared with the no exercise group (Fig. 2A). A non significant change in peak VO2 of −0.66 mL·kg−1 ·min−1 (95% CI: −2.05, 0.72, N = 48) was found for participants in the hydrotherapy group compared with conventional aerobic exercises (Fig. 2B). Three studies assessed the 6-minute walk test (6WMT) as an outcome [10,11,14], two compared hydrotherapy versus no exercise and one hydrotherapy versus aerobic exercises in land. Significant improvements were found when comparing hydrotherapy with no exercise controls. The meta-analyses showed (Fig. 3) a significant improvement in 6WMT of 43.8 m (95% CI: 7.36, 80.16, N = 42) for participants in the hydrotherapy group compared with the no exercise group. Three studies assessed muscle strength as an outcome, two compared hydrotherapy versus no exercise and one hydrotherapy versus aerobic exercise in land. Significant improvements were found when comparing hydrotherapy with no exercise controls. The meta-analyses showed (Fig. 4) a significant improvement in muscle strength of 23.7 Nm (95% CI: 4.49, 42.89, N = 42) for participants in the hydrotherapy group compared with the no exercise group. Two studies measured HRQOL. The meta-analyses showed non significant improvement in HRQOL of −4.5 (95% CI: −14.40, 5.49, N = 42) for participants in the hydrotherapy group compared with the no exercise group (Fig. 5). Meta-analysis demonstrated a significant difference in peak VO2, distance in the six-minute walking test, muscle strength and DBP between patients with HF submitted to hydrotherapy and controls. Moreover, hydrotherapy was as efficient as conventional aerobic exercise in land for peak VO2. It is now known that cardiac function actually improves during water immersion due to the increase in early diastolic filling and decrease in heart rate, resulting in improvements in stroke volume and ejection fraction. These data created a positive scenario to discuss hydrotherapy as a potential tool in cardiovascular rehabilitation. This systematic review with meta-analysis is important because it analyzes the hydrotherapy as a potential co-adjutant modality in the rehabilitation of patients with HF. The mean of peak VO2 in the analyzed studies was 17.05 at the beginning and 18.3 mL·kg−1 ·min−1 at the end of the intervention. It has been demonstrated that improvements above 10% after a cardiovascular rehabilitation program represent a good prognosis in patients with HF. It has also been demonstrated that a minimum VO2 peak of 15 mL·kg−1 ·min−1 in women and 18 mL·kg−1 ·min−1 in men aged 55–86 years seems to be necessary for full and independent living. Thus the improvement generated by the hydrotherapy program can contribute to those patients with CHF to have better conditions to carry out their everyday activities.




Quadriceps mass and strength are related to maximal exercise capacity in HF. Moreover, changes in muscle performance with exercise training have been demonstrated to be related to changes in physical function and quality of life. In the present systematic review, our meta-analysis demonstrated a significant difference in muscle strength between patients with HF submitted to hydrotherapy and sedentary controls. Despite the fact that hydrotherapy was shown to be efficient in improving peak VO2 and muscle strength, it is not possible to conclude about the benefits of hydrotherapy compared to no exercise in HRQOL. Considering the available data, our meta-analysis showed that hydrotherapy was efficient to improve exercise capacity in patients with HF. Well controlled RCTs are needed to understand the potential bene- fits of hydrotherapy in patients with HF.

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Idosos com osteoartrite de joelho obesos e não obesos

Durante o processo de envelhecimento, ocorrem perdas funcionais que se acentuam devido à falta de atividade do sistema neuromuscular e à redução da força muscular e do condicionamento físico. Além da redução da funcionalidade, o idoso perde de maneira mais acentuada a capacidade de reter água e de produzir proteoglicanos, o que causa alterações degenerativas articulares, como a osteoartrite (OA). Um dos fatores de risco para a OA é a obesidade. Além de ser um fator de risco para a OA, a associação entre OA e obesidade pode aumentar a intensidade da dor e das limitações funcionais, devido a uma maior descarga de peso na articulação acometida, com estreitamento do espaço intra‐articular, que pode aumentar a dor articular, rigidez e atrofia muscular. Numa recente metanálise que avaliou o risco para o inicio da OA, reportam que pessoas obesas têm três vezes mais risco de desenvolver OA em relação a indivíduos sem sobrepeso.

O peso excessivo aumenta tanto a pressão quanto a força sobre a articulação, ativa mecanismos de degradação da cartilagem articular, esclerose do osso subcondral e formação de osteófitos e leva ao agravamento da AO. Esses fatores podem influenciar negativamente na qualidade de vida (QV) de idosos obesos acometidos pela doença. A OA por si só ou em conjunto com a obesidade está associada a um maior risco de morbimortalidade e pode reduzir a QV do idoso. Um atributo essencial na saúde do idoso é a sua capacidade funcional, um componente chave para avaliação global da saúde. Além de ser fator de risco para a AO, a obesidade pode agravar sintomas e aumentar o declínio funcional de idosos com OA. Compreender fatores que interferem na capacidade funcional e QV de idosos com AO pode contribuir na formulação de estratégias de prevenção e tratamento. Diante disso, este estudo teve como objetivo comparar a capacidade funcional e a QV de idosos com OA de joelho, obesos e não obesos.

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Mansueto Gomes-Neto, Anderson Delano Araujo, Isabel Dayanne Almeida Junqueira, Diego Oliveira, Alécio Brasileiro, Fabio Luciano Arcanjo

Comparative study of functional capacity and quality of life among obese and non-obese elderly people with knee osteoarthritis

Revista Brasileira de Reumatologia (English Edition), Volume 56, Issue 2, March–April 2016, Pages 126-130

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